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THE 


PALiEONTOGRAPHICAL  SOCIETY. 


INSTITUTED  MDCCCXLVII. 


LONDON 


MDCCCCIV — MDOCCCXIII. 


MONOGRAPH  OF  THE  CRETACEOUS  LA:\IELLIBRANCHIA 

OF   ENGLAND. 

VOL.    ii. 


ORDER    OF    BINDING    AND    DATES    OF    PUBLICATION 


PAGES 

PLATES 

ISSUEU  IN  VOL. 
FOB   YEAB 

PUBLISHED 

General  Title-page  and  Contents 



1912 

February,  1913 

1—56 

I— VII 

1904 

December,  1904 

57—96 

VIII— XI 

1905 

November,  1905 

97—132 

XII— XIX 

1906 

December,  1906 

133—180 

XX— XXVII 

1907 

December,  1907 

181—216 

XXVIII— XXXIV 

1908 

December,  1908 

217—260 

XXXV— XLIV 

1909 

December,  1909 

261—284 

XLV— L 

1910 

January,  1911 

285—340 

LI— LIV 

1911 

February,  1912 

341—473 

LV— LXII 

1912 

February,  1913 

1"'^/  A     MONOGRAPH 


CRETACEOUS   LAMELIiBRANCHIA 


ENGLAND. 


BY 

he:^ry  woods,  m.a., 

UNIVERSITY    LECTURER    IN    PAL^OZOOLOOT,    CAMBRIDGE. 


VOL.    II. 


LONDON: 
PRINTED    FOR    THE    PAL^ONTOGRAPHICAL    SOCIETY. 

1904—1913. 


PUINTEI)    IIV     AULAKI)    \SI>    SON.    LONDON    AND    DOUKINQ. 


CONTENTS    OF    YOL.    TI. 


PAQB 

Ostrea    ... 

342 

Exogyra 

395 

Lima     ... 

1 

(Plagiostoma) 

10 

(Acesta) 

25 

(Mantellum) 

28 

(Ctenoides) . . . 

40 

„      (Limatula) ... 

45 

(Limea) 

53,425 

Pteria  (Oxytoma) 

57 

„      (Pseudoptera) 

63.425 

Aucella  ... 

69 

Aucellina 

72 

Gervillia 

74,425 

Perna    ... 

87 

luoceramus 

262,433 

Piuna    ... 

96 

Astarte... 

102 

„        (Eriphyla) 

113,426 

Opis 

118 

Cardita  ... 

121 

Cvassatellites 

128,426 

Anthouya 

130.426 

Cyprina... 

131.427 

Trapezium 

148 

Isocardia 

151 

Lucina  .. 

152 

Corbicella 

157 

Spbsera... 

157 

Mutiella 

160 

Unicardium 

162,428 

Thetironia 

165 

Tellina  ... 

171.429 

,,       (Palseomoera) 

173 

(Linearia) 

175 

Mactra  ... 

177 

Ptychomya 

179 

VI 


f 'R  KTAf'EOUS    LAMETJ.IBRANCHTA. 


PAQE 

Dosiniopsis           ...                                                              •••              •••                                                ••         1°^ 

Cypriinoria  (Cvtlorisma) 

183,431 

Clomentia  (Flavoutia) 

189 

Callista... 

.. 

192 

Tajies  (Icauotia)  ... 

.. 

431 

Protocanlia 

194 

Cardium 

201 

(Grauocariliiiin) 

205 

Toucasia 

207 

Gyropleura 

208 

Diirauia... 

420 

Corbula 

210 

Pharus... 

217 

Solecurtus  (Azor  ?) 

218 

Leptosoleu 

219,  432 

Pauopea 

■  . 

221 

Martesia 

.. 

231 

Turnus  ... 

233 

Teredo... 

237 

Plectomya 

238 

Anatiua  (Cercomya) 

238 

Thrac-ia... 

240.432 

Pholadoniya 

245 

Myopholas 

253 

GouioHiya 

254 

Pk'iiroinva 

256 

Liopistha  (Psilomvaj 

.. 

257 

Cuspidaria 

.. 

259 

Additions  and  Corrections 

423 

Tables  of  Distribution 

434 

Bibliography 

., 

.449 

Index 

462 

THE 


PAL.EONTOGRAPHICAL  SOCIETY. 


INSTITUTE  I)    :\II»('CCXLVir. 


VOLUME     FOR     1904. 


LONDON 


MDCCCCIV. 


A     MONOGRAPH 


CRETACEOUS    LAMELLIBRANCHIA 


OF 


ENGLAND. 


BY 


HENRY  WOODS,  M.A. 

UNIVERSITY    LECTUREK    IN    rALiOZOOLOGT,   CAMBRIDGE. 


VOL.  IL     PART  I. 
LIMID^. 

Pages  1— 5tj:   Plates  I— A'll. 


LONDON : 
PRINTED    FOli    THE    PAL.EONTOGKAPHICAL    SOCIETY. 

11)04. 


PRINTED   BY    ADLARD    AND    SON,    LONDON    AND    DOKKINO. 


DESCRIPTION    OF    SPF.CIES. 


Familij—LmmjE,  d'Orbignij. 

Genus — Lima,  /.  G.  llruguierc,  1797. 

('  Eucyc.  method.,'  Tabl.  Vers.,  pi.  ccvi.) 

Lima  canalifeka,  Gold/ass,  1836.     Plate    L 

1836.     Lima  canalifeea,  A.  Gohlf'uss.     Petref.  Germ.,  vol.  ii,  p.  89,  pi.  civ,  fig.  1. 
1839.       —  —  H.  B.  Geinitz.     Cliar.  d.  Schicht.  u.  Petref.  des  siiclis. 

Kreidegeb.,  pt.  i,  p.  24. 

—  —     MULTicosTATA,  Geinitz.     Ibid.,  p.  24,  pi.  viii,  fig.  3. 

1841.       —     CANALIFEEA,  F.  A.  Boiner.     Die  Versteiu.  d.  uord-deutscli.  Kreidegeb., 

p.  56. 

—  —     LATicosTA,  Romer.     Ibid.,  p.  57,  pi.  viii,  fig.  9. 

1843.       —     MVh-ncosTATA,  H.  B.  Geinitz.    Die  Versteiu.  von  Kiesliugswalda,  p.  23, 

pi.  vi,  fig.  10. 
1846.       —     LATICOSTA,  A.  E.  Beuss.     Die   Verstein.   der  bohm.  Kreideformat., 

pt.  2,  p.  34. 

—  —     MtTLTicosTATA,  Beuss.     Ibid.,  p.  34,  pi.  xxxviii,  figs.  7,  8,  18. 

—  —  —  H.  B.  Geinitz.     Grimdr.  d.  Versteiu.,  p.  472. 

1850.       —     CANALIFEEA,  Geinitz.     Das  Quadersaudst.  oder  Kreidegeb.  in  Deutsch- 

laud,  p.  190. 

—  —     MULTICOSTATA,  Geiuitz.     Ibid.,  p.  192. 

—  —     CANALIFEEA,  A.  (VOrhi<jHij.     Prodr.  de  Pal.,  vol.  ii.  p.  167. 
?     —  —     MULTICOSTATA,  d'Orhiijmj.     Ibid.,  p.  248. 

—  —     LATICOSTA,  d'Orltigny.     Ibid.,  p.  249. 

1863.       —    CANALIFEEA,  A.  Kiinth.     ZeitscliT.  d.  deutsch.  geol.  Gesellsch.,  vol.  xv, 

p.  726. 

—  —  —  B.  Drescher.     Ibid.,  vol.  xv,  p.  356. 

?  1868.       —     MULTICOSTATA,  E.  Eichwakl.     LetLsea  Kossica,  vol.  ii,  p.  459. 

1870.       —    MULTicosTA,  F.  J.  Piclet  and  G.  Campiche.      Foss.  Terr.  Crct.  St«?. 

Croix  (Mater.  Pal.  Suisse,  ser.  5),  p.  174. 

—  —     CANALIFEEA,  Pictet  and  Campiche.     Ibid.,  p.  175. 

1872.       —  —         H.  B.  Geinitz.     Das  Elbthalgeb.  iu  Sachsen  (Palroon- 

tographica,    vol.   x.\,   j)!.   2).   p.   38, 
pi.  ix,  tigs.  6 — 8. 

1 


2  CRETACEOUS   LAMELLIBRAXCHIA. 

1876.  Lima  canalifera,  D.  Brauns.    Zeitschr.  f .  d.  gesammt.  Natui-wiss.,  vol.  xlvi, 

p.  386. 

1877.  —  —  A.  Fritsch.     Stud,  im  Gebiete  der  bohin.  Kreidofuruiat. : 

II,  Weissenberg.    u.   Mabiitz.    Scliiclit., 
p.  132,  fig.  117. 
1893.       —    cf.    CANALIFEEA,  B.  Miclutd.     Zeitschr.  der  deutscli.  geol.  Gesellsch., 

vol.  xlv,  p.  242. 
189g.       —     CANALIFEEA,  G.  Midler.     Mollusk.  Uuterseuou.  v.  Braimscliweig  u. 

Ilsede  (Abhaudl.  d.  k.  preussiscli.  geol. 
Landesaust.  N.F.,  Heft  25),  p.  28. 
lyOl.       —  —  if.  Imheller.    Kreidebild.    am    Stallauer   Eck   (Palaeou- 

tograpliica,  vol.  xlviii),  p.  32,  pi.  iii,  fig.  10. 
—         —  —  F.  Sturm.     Jabrb.  d.  k.  preussisch.  geol.   Landesaust. 

fiir  1900,  vol.  xxi,  p.  90. 

Description. — Sliell  moderately  convex,  oval  or  subtriangular ;  height  a  little 
greater  than  length ;  outline  rounded,  except  the  antero-dorsal  margin,  which  is 
nearly  straight  and  rather  long.  Apical  angle  from  105°  to  110°.  Umbones 
rather  small,  close  together.  Anterior  area  slightly  depressed,  with  small  radial 
ribs.  Anterior  ears  small ;  posterior  larger,  with  growth-lines  and  faint  radial 
ribs. 

Ornamentation  consists  usually  of  18,  but  sometimes  of  as  few  as  14  or  as  many 
as  21  very  strong,  rounded,  straight  ribs,  which  are  separated  by  broader  furrows. 
In  well-preserved  specimens  numerous  concentric  linear  ridges  occur  on  both  rijjs 
and  furrows,  and  projecting  growth-ridges  are  seen  at  regular  intervals  on  the 
ribs. 

teasurements  : 

(3)  (1)  (5) 

.       52       .       43       .       32  mm. 
.       54       .       44       .       35     „ 

(1 — 6)  Uj^per  Grreensaud,  Ventnor. 

Ajjlnities. — An  exact  comparison  of  the  English  specimens  with  the  foreign 
examples  of  Limn  canalifera  is  rendered  difficult  owing  to  the  fact  that  the  former 
have  the  shell  well  preserved  Avhilst  the  latter  occur  chiefly  as  casts.  In  both 
cases  the  number  and  breadth  of  the  ribs  show  considerable  variation.  The  fine 
concentric  ornamentation  is  the  same  in  both,  as  is  shown  by  Goldfuss'  figure,  but 
in  some  of  the  best  preserved  English  specimens  there  occur  also  transverse 
ridges  on  the  ribs  at  regular  intervals.  Somewhat  similar  ridges  are  shown  in 
Goldfuss'  figure,  but  they  seem  to  be  present  chiefly  on  the  sides  of  the  riljs  and 

'  In  all  species  of  Lima  (unless  otherwise  stated)  this  is  moasured  obbquelv  to  the  hiui;e-Uue  so 
as  to  give  the  greatest  height . 


Measurements  : 

(1) 

(2) 

Length 

7(» 

.       56 

Height' 

70 

58 

LIMA.  3 

in  the  neighbourhood  of  the  umbo  only.  With  the  exception  of  tliis  cliaracter  the 
Eng-b'sh  specimens  agree  closely  with  the  foreign  examples,  and  this  difference 
may  very  well  lie  due  to  the  latter  being  much  less  perfectly  preserved  than  the 
former.  Moreover,  in  some  English  specimens  the  ridges  mentioned  are  partly  or 
entirely  wanting. 

The  English  examples  occur  at  a  lower  horizon  than  those  found  abroad, 
namely,  in  the  zone  of  Feden  oftj^er.  The  foreign  specimens  are  found  in  the 
Turonian  and  Senonian,  and  possibly  also  in  the  Cenomanian,  and,  like  the  English 
examples,  they  occur  chiefly  in  beds  of  a  sandy  nature.  This  last  fact  may  account 
for  the  absence  of  the  species  in  the  English  Chalk,  during  the  deposition  of  which 
the  sea-iloor  was  formed  of  ooze  and  was  at  a  greater  depth. 

Lima  Etalknii,  Pictet  and  Campicho,'  from  the  Yalauginian,  presents  some 
resemblance  to  L.  canalifera,  but  has  a  smaller  apical  angle ;  the  character  of  its 
fine  ornamentation  is  unknown. 

Type. — Goldfuss'  specimens  came  from  the  Senonian  of  Quedlinl)urg,  Haltern 
and  Regensburg. 

fi/.'^friliiifiov. — Upper  Greensand  (zone  of  Frrirn  a><]irr)  of  Vontnor. 


Ltma  GAT.T.TENNKr,  iVOrhi(jmi,  1847.     Plate  II,  figs.  1'/ — c. 

1847.     Lima  Gallienniana,  A.  d'Orbigny.     Pal.  Franc.  Terr.  Crrt.,  vol.  iii,  p.  548, 

pi.  ccccxx,  figs.  1 — 3  {GalUennei  on 
plate) . 
1850.       —  —  —  Proclr.  de  Pal.,  vol.  ii,  p.  166. 

1854.       —      Galliennei,  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  171. 
1867.       —  —  E.   Gve'ranger.     Allium  Pak'ont.  de   la    Sarthe,   p.   18, 

pi.  xxiii,  figs.  23,  24. 
1869.       —  —  F.J.  Fictci  and  G.  Camjnche.     Foss.   Terr.    Cri't.   Sto. 

Croix  (Mater.  Pal.  Suisse,  ser.  5). 
p.  168. 
1871.  Eadula  Galliennei,  F.  Sloljczka.     PaloDont.  Iiidica,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  414. 

J)r.<!rnpfi(iv. — Shell  compressed,  more  or  less  oblong  with  rounded  margin  ; 
height  greater  than  length.  Antero-dorsal  margin  straight  or  slightly  coTicave. 
Apical  angle  large.  Umbones  close  together.  Anterior  area  only  slightly  depressed, 
with  sharp  borders. 

Ornamentation  consists  of  12  to  15  strong,  much  elevated   ribs  with  roimded 

1  •  Terr.  Crut.  Ste.  Croix'  (1869),  p.  141.  pi  dxiv,  fig.  3. 


4  CRETACEOUS   LA^IELLIBRAKCHIA. 

su  mmits,  separated  by  broader  rounded  hirroTvs.     Both  ridges  and  furrows  bear 

numerous  flattened    radial    ridges    separated    by    lincai'    grooves;    the  ridges,   in 

Avell-proserved  specimens,  are  serrate  or  granular.      At    distant    intervals   a   few 

woll-mai'kcd  growth-ridges  occur. 

Measurements : 

(1)  (2) 

Length         .         49         .         70  mm. 

Height         .         54         .         78    „ 
(1,2)  Upper  Greensand,  Devizes. 

Affinities. — This  species  is  distinguished  from  L.  canalifera  (p.  1)  by  the 
valves  being  more  compressed,  the  ribs  fewer  in  number,  the  grooves  relatively 
broader,  and  by  the  presence  of  fine  radial  ornamentation  on  the  ribs  and  grooves. 

Remarhs. — This  appears  to  be  a  rare  species  in  England.  The  specimens  from 
Devizes  are  in  the  Museum  of  Practical  Geology.  The  specimen  from  Humble 
Rocks  was  collected  by  Mr.  Jukes-Browne,  and  is  now  in  the  Sedgwick  Museum. 

Ti/pr. — From  the  Cenomanian  of  Coudrecieux,  Sarthe. 

Distrlhiitlon. — Upper  Greensand  (zone  of  ScJiloenharhia  rostra ta)  of  Devizes. 
Base  of  Chalk  Marl  (Bed  10)  of  Humble  Rocks,  West  of  Lyme  Regis. 


Lima  vectensts,  sp.  nov.     Plate  II,  figs.  2,  a — c. 

'Description. — Shell  large,  rather  compressed,  ovate,  height  greater  than  length; 
antero-dorsal  margin  straight,  the  remainder  forming  a  regular  curve.  Anterior 
area  deeply  depressed.  Apical  angle  apparently  about  100°.  Anteinor  ear  small; 
posterior  ear  larger,  with  a  few  ribs. 

Ornamentation  consists  of  about  40  rather  strong,  narrow  ribs,  with  rounded 
summits  which,  in  places,  are  slightly  tubercular.  The  ribs  are  closer  together  on 
the  anterior  part  of  the  valves  than  elsewhere.  The  interspaces  are  much  broader 
than  the  ril)S,  and  are  flat  or  slightly  concave ;  they  are  marked  by  numerous  fine, 
concentric  ridges. 

Afinities. — This  species  resembles  Lima  Dujnrdini,  Deshayes,^  from  the 
Senonian,  but  the  interspaces  are  flat  or  nearly  flat  instead  of  concave,  and  the 
well-marked  scale-like  projections  which,  in  L.  Dujardini,  are  placed  at  intervals 
on  the  ribs,  l)ut  without  a  concentric  arrangement,  are  not  seen. 

1  Dujardin,  'Mem.  Soc.  guol.  de  France,'  vol.  ii  (1837),  p.  227.  pi.  xvi,  fig.  3.  D'Orbignv,  'Terr. 
Crct.,'  vol.  iii  (1847),  p.  569,  pi.  ccccxxvii,  figs.  1 — i. 


LIMA.  5 

Bemnrls. — I  have  seen  one  example  only;  it  consists  of  both  valves,  but  with 
the  posterior  margin  imperfect. 

Type. — In  the  Museum  of  the  Vcntnor  Institute. 

Distribution. — Upper  Grreensand,  chert  l)otls  (zone  of  Pecten  asper)  of  tlic  Isle 
of  Wight. 


LrMA  SHBOVAUS,  S(mprt)ij,  183G.     Plate  II,  figs.  3,  4a,  /*,  ba,  h,  Ga,  h,  7a,  h. 

1836.     Lima  ?  suBovALis,  /.  de  G.  Sowerby.      Trans.  Greol.  Soc,   ser.    2,  vol.  iv, 

pp.  359,  342,  pi.  xvii,  fig.  21. 
1830.       —      ASPEEA,    H.    B.    Ge'iiiitz.      Oliar.    cl.   Scliicht.   u.   Petref.    des   silclis. 

Kreidegeb.,  pt.  1,  p.  23  (pariim). 
?  1847.       —      SUBOVALIS,  A.  d'Archiac.     Mt'm.  Soc.  geol.  de  France,  ser.  2,  vol.  ii, 

p.  309. 

—  —       OKNATA,   A.    d'Orhujmj.     Pal.   Fran9.    Terr.    Crct.,    vol.  iii,   p.   551, 

pi.  ccccxxi,  figs.  6 — 10. 
1850.       —  —  —  Prodr.  de  Pal.,  vol.  ii,  p.  167. 

—  —  —         H.  B.   Geinitz.      Das   Quadersandst.    oder   Kreidegeb.    in 

Deutschland,  p.  192. 
1867.       —  —         E.    Gueranger.     Album   Pak'ont.   de    la    Sarthe,    p.     19, 

pi.  xxiv,  figs.  7,  12. 

1869.  —       SUBOVALIS,  F.  J.  Pidet  and  G.  Campiche.     Foss.  Terr.  Crct.  Ste. 

Croix  (Mater.  Pal.  Suisse,  ser.  5), 
p.  168. 

1870.  —       OENATA,  Pictet  and  Cavqnche.     Ibid.,  pp.  169,  173. 

1871.  Eadula  (Acesta)  ornata,  F.  Stoliczka.     Palseont.  Indica,  Cret.  Fauna  S. 

India,  vol.  iii,  p.  414. 

1872.  Lima  oenata,  H.  B.  Geinitz.     Das  Elbtlialgcb.   in  Sachsen  (Palasoutogra- 

pliica,   vol.    XX,   pt.    1),    p.    205,   pi.    xlii, 
figs.  16,  17. 
?  1877.       —  —A.  Peron.     Bull.  Soc.  gi'ol.  do  France,  ser.  3,  vol.  v,  p.  502. 

1877.       —      Eauliniana,  A.  J.  Jukes-Browne.     Quart.   Journ.    Geol.    Soc.,   vol. 

xxxiii,  p.  502,  pi.  xxi,  fig.  2. 
1893.       —      ornata.  R.  Michael.     Zeitschr.  d.  doutsch.  geol.  Gescllscli.,  vol.  xlv, 

p.  234. 

Non  1852.       —  —        A.  Buvignicr.     Statist,  gi'ol.,  etc.,  de  la  Meuse,  Atla.'s.  p.  23. 

pi.  xviii,  figs.  17 — 19. 

Bescription. — Shell  compressed,  ovate  or  subtrigonal,  oblique,  consideral)ly 
higher  than  long,  with  the  ventral  and  posterior  margins  rounded.  Apical  angle 
about  74°.  Umlwnes  small,  close  together.  Anterior  area  rather  small,  dejn-esscd, 
limited  hy  a  ridge,  ornamented  with  ribs  separated  by  broader  grooves. 

Ornamentation  consists  of  numerous  (C-5  to  70)  fairly  strong,  rounded  libs  of 


6  CRETACEOUS   LA:\IELLIBT{ANCHTA. 

nearly  equal  size,  but  sometimes  (chiefly  near  the  posterior  l)or(l('r)  with  smaller 
intercalated  ribs.  The  ribs  diverge  slightly  from  a  nearly  median  line,  and  bear 
short  spiny  or  scaly  projections  at  regular  intervals  but  not  usually  with  a  con- 
centric arrangement.  The  spines  are  rather  nearer  the  inner  than  the  outer  side 
of  each  rib.  The  gi-ooves  are  narrow  near  the  umbo  but  become  broader  in  passing 
ventrally,  and  at  the  ventral  margin  may  exceed  the  ribs  in  breadth.  The  grooA-^es 
are  rounded  and  (in  some  specimens)  show  transverse  ridges.  More  or  less  distinct 
"•rowth-lines  occur  at  intervals. 
Mffis^urements : 

(1)  (2)  (3)  (4)  (5)  (6) 

Length     .     25     .     21     .     20     .     17     .     16     .     It  luni. 
Height     .     U     .     28     .     29     .     23     .     23     .     20    „ 
(1,3)  Cambridge  Greensand. 

(2)  Base  of  Chalk  Marl,  Folkestone. 
(4,  5)  Upper  Greensand,  Warminster. 
(G)       ,,  „  Haldon. 

Affinities. — This  species  belongs  to  the  same  group  as  the  Senonian  forms  L. 
Dtnikcri,  Hagenow,^  and  L.  muricafa,  Goldfuss."  It  is  distinguished  from  the 
former  by  its  smaller  apical  angle  and  by  the  spines  on  the  ribs  being  placed  more 
closely  together.  L.  muricata  differs  from  L.  suhovalis  in  ha\^ng  fewer  ribs  with 
their  ornamentation  developed  into  long  scale-like  projections,  and  in  having 
oblique  grooves  in  the  interspaces. 

Bcmarlcs. — A  comparison  of  the  type  of  Lima  mhovalis  with  examples  of  L. 
oriKitd  leaves  no  doubt  as  to  their  identit)\  The  type-specimen  of  the  former  is 
somewhat  worn,  but  sufficiently  well-preserved  for  identification,  and  another 
specimen  on  the  same  tablet  shows  the  ornamentation  quite  clearly ;  the  shell  is  not 
silicified,  so  that  it  was  evidently  not  obtained  from  Blackdown — the  locality  given 
by  Fitton — but  it  has  all  the  appearance  of  specimens  found  at  AYarminstcr. 

The  examples  from  the  Candiridge  Greensand  were  referred  to  L.  UnuUmana, 
d'Orbigny,'  by  Mr.  Jukes-Browne.  The  interior  of  these  is  filled  Avith  phosphate, 
and  the  shell,  although  in  some  respects  well-preserved,  is  rather  abraded,  so  that 
the  remains  of  the  spines  usually  appear  as  notches  on  the  inner  side  (that  facing 
the  median  line)  of  each  rib.  The  transverse  ornamentation  in  the  grooves  is  often 
very  distinct.  Mr.  Jukes-Browne  has  recently  re-exAmined  these  specimens  and 
agrees  with  mc  in  thinking  that  they  cannot  be  separated  from  L.  svhovaJis.     I 

1  '  Neues  Jahrl).  fiir  Miu.,  etc'  (1842),  p.  556;  Vogel,  'Holliind.  Krcide  '  (1895),  p.  17,  pi.  i,  fiy.  9: 
Ravn,  'Mollusk.  Danmarks  Kridtaflej.'  (1902),  p.  100,  pi.  ii.  fig.  14. 

-'  '  Petref.  Germ.,'  vol.  ii  (1836),  p.  89,  pi.  ciii,  fig.  4;  Vogel,  oj}.  cit.,  p.  17,  pi.  i,  figs.  10,  11. 

'  '  Pal.  Fran?.  Terr.  Cn't.,'  vol.  iii  (1847),  p.  542,  pi.  ccccxvii,  figs.  5—8;  '  Prodr.  de  Pal.'  (1850), 
vol.  ii,  p.  138;  Pictet  and  Campiche,  "  Foss.  Terr.  Cn't.  Ste.  Croix"  ('Mater.  Pal.  Suisse,'  ser.  5, 
1869),  p.  154.  pi.  clxvi,  fig.  2. 


LIMA.  7 

have  uot  beeu  able  to  obtain  specimens  of  i.  Rauliniuiui,  but  it  seems  to  tlil'fer  from 
L.  mhovalis  in  having  a  hirgor  posterior  ear  and  in  other  characters. 

Tijpe>i.—l\\  the  Bristol  Museum  (No.  1778),  from  the  Upper  Greensand,  proba])]y 
of  Warminster.  The  type  of  L.  ornnta  is  from  the  Cenomanian  of  Le  Mans.  Tlie 
specimen  from  the  Cambridge  Greensand  figured  by  Jukes-Browne  is  in  the 
Sedgwick  Museum,  Cambridge. 

Distribution. — Upper  Greensand  (zone  of  Sc1dujub<(<:hi(i  rudynta)  of  Haldon. 
Upper  Greensand  (zone  of  Pecten  asper)  of  North  Dorset,  and  Warminster.  Cam- 
bridge Greensand  (derived).  Rye  Hill  Sand  of  Maiden  Bradley.  Chloritic  Marl 
of  Rocken  End  (Isle  of  Wight).  Base  of  Chalk  Marl  (Greensand  bed)  of  Folkestone. 
Also  recorded  by  the  Geological  Survey  from  the  Cenomanian  of  Devon  and  Chard. 


Lima  scabrissima,  sp.  nov.     Plate  II,  figs.  8a,  b,  9 a,  b. 

Description. — Shell  compressed,  ovate,  height  greater  than  lengtli ;  autei'u- 
dorsal  margin  rather  short,  straight  oi'  slightly  concave,  ventral  and  posterior 
margins  forming  a  regular  curve.  Anterior  area  much  depressed,  sharply  limited, 
nearly  smooth  oi'  with  faint  ribs.  Apical  angle  about  92°.  Posterior  ear  of 
moderate  size,  with  distinct  growth-lines ;  anterior  ear  small. 

Ornamentation  consists  of  a  large  number  of  narrow,  rounded,  more  or  less 
undulating  ribs  separated  by  broader  grooves.  The  ribs  are  generally  of  nearly 
equal  size,  but  smaller  ones  may  be  intei'calated  in  the  grooves.  At  regular 
intervals  the  ribs  bear  scales  or  lappet-like  projections  which  are  arranged  con- 
centrically and  may  become  vertical  at  their  ends ;  these  scales  are  continued 
across  the  grooves  as  laminar  projections.  On  the  anterior  and  posterior  ribs  the 
"  scales  "  become  more  pointed. 

Measurements  : 

(1)  (2)  (3) 

Length  .         54  .  52  .  38  mm. 

Heiffht  .62  .  58  .  42    „ 


'1-1 


(1 — 3)  Upper  Groonsaiul,  Wuruiiiistor. 


Affinities. — This  species  is  near  to  LiiiM  rhotoiiuujensii,  d'Orbigny,'  from  the 
Cenomanian  of  Rouen,  but  is  distinguished  from  it  by  being  nuich  less  convex,  by 
having  a  smaller  anterior  area  and  a  smaller  apical  angle,  and  by  the  ribs  being 
relatively  narrower  and  the  grooves  broader. 

TyjJes. — In  the  Museum  of  Practical  Geology. 

Distribution. — Upper  Greensand  (zone  of  Pecten  as2)er)  of  Warminster. 

1  'Pal.  Franv.  Terr.  Crct.,"  vol.  iii  (18-i7),  p.  5.57,  pi.  coccxxii,  tigs.  8—11. 


CRETACEOUS   LAMELLIBRANCIIIA. 


Lima  asfeka  {MaitUil)  1822.     Pkitc  II,  figs.  10,  11  ;  riale  III,  figs.  \a,h,  2-4. 

1822.     Plagiostoma  ?  aspeea,  G.  Mantell.   Foss.  S.  Downs,  p.  129,  pi.  xxvi.fig.  18. 
1854.    Lima  aspera,  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  170. 

1870.  —  —       F.  J.  riciet  a7id  G.   Cavqiichc.     Foss.  Terr.  Crct.  Sto.   Croix 

(Mater.  Pal.  Suisse,  ser.  5),  p.  169. 

1871.  Kadula  (?  Acesta)  aspeka,  F.  StoliczJca.     Palaeout.  ludica,  Cret.  Fauua  S. 

India,  vol.  iii,  p.  41.'). 
1903.     Lima  aspeea,  A.  J.  Jukes-Browne.     Cret.  Eocks  of  Britain  (Mem.  Geol. 

Survey),  vol.  iii,  p.  450. 

Nou  1830.       —  —       A.  GohJ/uss.     Petref.  Germ.,  vol.  ii,  p.  90,  pi.  civ,  fig.  4. 

—  1839.      —  —       H.  B.  Geinitz.      Char.    d.    Scliicht.    u.   Petref.   des   sachs. 

Kreidegeb.,  pt.  1,  p.  23,  pi.  xxi,  fig.  10. 

—  1841.      —  —       F.  A.  RiJmer.     Die  Verstein.  d.  uord-deutsch.    Kreidegeb., 

p.  56. 

—  1846.       —  —       A.  E.  Bkuss.     Die  Verstein.  der  bohm.  Kreideformat.,  pt.  2, 

p.  34,  pi.  xxxviii,  fig.  17. 

—  1847.       —  ~       A.  d'Orbujiii/.     Pal.   Frau^.   Terr.  Cri't.,  vol.   iii,  p.  506,  pi. 

ccccxxv,  figs.  3—0. 

—  1850.       —  —  —  Prod,  der  Pal.,  vol.  ii,  p.  248. 

—  —         —  —       A.  Alth.     Besclu'eib.  d.  Umgebuug  vonLemberg  (Haidiuger's 

Naturwiss.  Abliandl.,  vol.  iii,  pt.  2),  p.  243. 

—  1803.       —  —       A.   V.   Stromheck.      Zeitscbr.    d.    deutsch.    geol.   Gesellsch.. 

vol.  XV,  p.  150. 

—  1869.       —  —       E.  Favre.     Moll.  Foss.  de  la  Craie  de  Lemberg,  p.  135. 

—  1870.       —  —       F.  J.  Pidet  and  G.  Campiche.     Foss.  Terr.  Cret.  Ste.  Croix 

(Mater.  Pal.  Suisse,  ser.  5),  pp.  171,  173. 

—  1877.       —  —       A.  Fritsch.     Stud,  im  Gebiete  der  bohm.  Kreideformat.  ;  II, 

Die  Weissenberg.  u.  Maluitz.  Schiclit.,  p.  132, 
fig.  118. 
_    1883.       —  _  _  Ibid.,  Ill,  Die  Iserschicht.,  p.  114. 

—  1887.      —  —A.  Peron.     L'Hist.  Terr,  de  Craie  (Bull.  Soc.  Sci.   hist,  et 

nat.  de  I'Yonne,  ser.  3,  vol.  xii),  p.  150. 

—  1889.       —      (Plagiostoma)   aspeea,   0.   Griepenlcerl.     Seuou.  von   Konigslutter 

(Pala;ont.  Abhandl.,  vol.  iv),  p.  40. 

—  1898.       —      aspeea,  G.  Mailer.     Mollusk.    Untersen.  v.  Braimschweig  u.  Ilsede 

(Abhandl.  d.  k.  preussiseh.  geol.  Landesanst., 
N.F.,  Heft  25),  p.  20,  pi.  iv,  tig.  5. 

—  1900.       —  —       C.  Gagel  and  F.  Kaunhowen.     Jahrb.  d.  k.  preussiseh.   geol. 

Landesanst.  fiir  1899,  p.  232. 

Description. — Shell  ovate,  liiglier  than  long,  outline  rounded,  with  the  antero- 
dorsal  and  postero-dorsal  margins  straightened;  convexity  small.  Umbones  small, 
pointed,  close  together,  apical  angle  80°  to  90''.     Anterior  urea    deep,   narrow. 


LIMA.  .) 

Anterior  ears  triaiio-ular,  ratlicr  small  :  jinstcrioi-  cai's  obtusely  triaii^iilai',  eloiio-ato, 
with  radial  ribs. 

Valves  ornamented  with  numerous  flattened  ril)s  arranged  on  eithei'  side  ol'  a 
line  passing  from  the  umbo  to  the  ventral  margin,  fi'om  which  they  diverge  sliglitly. 
The  ribs  are  nearly  straight  or  sliglitly  undulating,  but  are  often  bent  abruptly 
where  they  cross  growth-lines.  Surface  of  ribs  nearly  smooth,  l)ut  sometimes 
showing  very  fine  concentric  ridges  or  (when  worn)  ojjlique  stria\  On  the  inner 
edge  of  each  rib — that  facing  the  middle  line — there  arc  short,  slit-like  indentations, 
above  each  of  which  a  short  spiny  projection  is  seen  in  perfectly  preserved 
specimens.  These  slits  and  spines  do  not,  as  a  rule,  show  a  concentric  arrange- 
ment. The  grooves  separating  the  ribs  are  very  narrow  and  are  mnvked  with 
pits  near  the  umbo  and  with  transverse  grooves  ventrally.  Sometimes  near  tlie 
margins  of  the  valves  new  ribs  are  intercalated  or  old  ones  bifurcate. 

Measurements : 


(I) 

(2) 

(.'5) 

(+) 

(5) 

(6) 

(7) 

Length  .     .     .     . 

31 

.     30     , 

.     28     , 

.     26 

.     24. 

.     10     , 

1  6  nun. 

Height  .     .     .     . 

3G     . 

,     33     . 

,     33     . 

,     35     . 

,     26     . 

23     . 

21     „ 

Nuiu])er  of  I'ibs    . 

or.    , 

.     -il     , 

,     GO     . 

.     4G     , 

.     42     , 

,     41     . 

r,2 

(1,2,  3,  7)  Totterulioe  Stone,  Burwell. 

(4)  „  „      Cherry  Hinton. 

(.5,  6)  Chalk  Marl,  Folkestone. 

Affiuifies. — The  Seuonian  form  figured  as  Liimt  aspcra  by  Goldfuss,  Reuss,  and 
Fritsch  is  clearly  distinguished  from  this  species  by  the  chevron-like  ornamentation 
on  the  ribs.  Pictet  and  Campiche  suggest  that  Goldfuss'  species  may  be  identical 
with  Liu)ii  Pin/l-cri,  Hagenow,'  from  Riigen,  ])ut  this  view  is  not  supported  by  the" 
figures  given  by  Vogel  and  Ravn.  The  form  figured  by  d'Orbigny  has  a  larger 
apical  angle  than  L.  nspera,  Mautell,  and  does  not  show  the  spiny  projections  on 
one  side  of  the  i'il)S. 

The  example  figured  by  Reuss"  as  TAiiki  lilana  is  similai'  in  form  to  T,.  (iKjtero, 
Mantell,  Init  does  not  appear  to  possess  the  spiiiy  projections  on  the  ril)s. 

Tijpi's. — I  have  not  been  able  to  find  the  tyjies.'*  They  came  from  the  ("halk 
Marl  of  Harasey  and  Stoncham. 

DisfriliHtian. — Chloritic  Marl  of  Kastbout  uc.  Chalk  Marl  of  Folkestone,  and 
Blue  Bell  Hill  (Bui-ham).  'i'ottei-ulioe  Stone  of  Arlesey,  Burwell,  Cherry  liinton. 
and  Stoke  Ferry. 

'  'Neues  Jalirb.  ftir  Mm.,'  etc.  (1842),  p.  55G. 

-  'Verstein.  bohmisch.  Krcidcformat.'  (184r)),  p.  35,  pi.  xxxviii,  fi<if.  20. 

•''  Tlie  name  nnjM'ra  was  used  by  Chonuiity,  (1784)  for  a  recent  species  of  Lima,  Init  since  tliat  has 
been  sliown  to  be  a  synonym  of  Lima  scahra  (Born,  1780)  there  does  not  appear  to  be  sufficient  reason 
for  1,'iviii^'  a  new  niuiic  tn  tin-  Cli:ill<  species  whicli.  for  over  oiLjhty  years,  ha.s  Won  known  as  T,imn 
asjx'i'".  Mantelt 


10 


CEETACEOTS    L.\:\IETJJEEAXrTTTA. 


Suh-gC)1llft Pr-AlilOSTOMA,  J.   So/rfrhij,  181k 

('Mill.  Conoli.,'  vol.  i,  j>.  176.) 

IiiM.\  (Pf.AGiosTOMA)  suBHiaiDA,  Rumcr,  1836.     Plate  Til,  figs.  Tx/,  Ji,  (5 — *.».     Text- 
figs.  1,  2,  8. 

1836.     Lima  subrigida,  F.  A.  Riimer.     Verstein.  uord-Jcutsch.  Oolithen-gcb.,  p.  79, 

pi.  siii,  fig.  16. 

—  —      PLANA,  Rimer.     Ibid.,  p.  80,  pi.  xiii,  fig.  18. 

1841.       —      SUBKIGIDA,  Bomer.     Die  Verstein.  cl.  uord-deutsch.  Kreidegel).,  p.  57. 

—  —      PLANA,  El'imer.     Ibid.,  p.  67. 

1877.       —      suBEiGiDA,  (t.  JS/i^w.      Zeitschr.  d.  deutscli.  gcol.  Gesellscli.,  vol.  xxix, 

p.  235. 
1896.       —  —  A.  Wollemann.      Ibid.,  vol.  xlviii,  p.  836. 

1900.       —  —  Wollemann.     Die  Biv.  u.  Gastrop.  d.  deutsch.  u.  hoUiiiid. 

Neocoms  (Abliandl.  d.  k.  preiissich.  geol. 

Land.,N.F.,  pt.  :51),  p.  30. 


Fia.  1. — Limn  {Plagiostoma)  suhHgida,'RomQv.    C'laxliy  Ironstono,  Lincolnsliire.    Right  valve.     Natural  sizo. 

Sedf^wick  Museum,  Camliridgc. 

Description. — Shell  convex,  oval,  height  sliglitly  greater  th;iii  length  ;  initcro- 
dorsal  margin  nearly  straight,  postcro-doi'.^nl  inucli  sliortcr  and  nearly  straight,  tlic 
remainder  ronnded  and  forminor  a  regular  curve.      Ai)ical  aiiirle  rather  more  than  a 


LIMA. 


11 


right  uiigle.  Uml)ones  of  moderate  size.  Area  large,  with  a  hirge  triangular 
ligament  pit  near  the  middle  but  bending  posteriorly.  Anterior  area  large,  deeply 
depressed,  especially  near  the  ears.  Ears  rather  large,  the  anterior  triangular,  the 
posterior  rather  larger,  more  elongate ;  surface  with  growth-lamellae  only. 

Surface  ornamented  witli  numerous  (43  to  52)  radial  ribs,  which  are  straight  or 
slightly  undulating.  The  ribs  are  flattened;  near  the  uml)o  they  are  separated  by 
Tuxrrow  grooves,  but  in  passing  ventrally  the  grooves  increase  in  width  and  become 
as  wide  as  or  wider  than  the  ribs.  The  grooves  are  rather  shallow  and  rounded. 
The  anterior  and  posterior  ribs  are  narrower  than  the  others.  Near  the  umbo  the 
grooves  are  punctate,  but  in  passing  ventrally  the  pits  soon  become  replaced  by 


Fio.  2. — Lima  {Plaijiostoma)  subrigida,  Romor.     C'laxby  Ii-onstono,  lionuiwortli  Haven.     Right  valve. 

Natural  size.     Sedgwick  Museum. 

transverse  furrows  separated  by  ridges,  and  the  latter  may  pass  on  to  the  ribs. 
the  anterior  area  ribs  are  small  or  absent,  but  growth-lines  are  usually  distinct. 
Measurements  : 

(1)  (2)  (3) 

Kt'.i  100  80 

111  1 08  85 

—  (J3  — 

48  49  48 


On 


Length 
Height 
Thickness 
Number  of  riljs 


(i) 

(5) 

Ci) 

(7) 

(8) 

(9) 

73 

72 

ill 

()3 

38 

31  mm. 

79 

7i; 

()5 

05 

30 

40  „ 

51 

k; 

1-3 

ol) 
52 

52 

44 

(1 — 9)  Claxhy  IroustoiK',  Beuuiworth  Haveu. 

Affinities. — L.     rii/nrnlriisis,     Pictet     and     Campiche,'    is    distinguished    from 
L.  subrigida    by  its  more   (luadrilateral    outline,   more  luunerous    ril)s    and    finer 
>  'Ton-.  Civt.  Ste.  Croix'  (1869),  p.  138,  \A.  clxii,  fiijs.  5—8. 


12  CRKTACEOUS    l,AMKi;iJRRAN(M[T.\. 

grooves,  ami  alsij  liy  the  eai'liiT  part  of  the  sliell   heiiii;'  nearly   sinoutli.      //.  mihcr- 
soneusis,  Pictet  and  Caiii]iiclR','  is  relatively  longer  and  has  narrower  grooves. 

Remarks. — On  account  of  the  imperfect  figures  of  L.  s/iliriijiiln  niven  by  Romer, 
the  English  specimens  have  not  hitherto  been  referred  to  that  species;  they  agree 
perfectly  with  the  descriptions  except  in  the  number  of  ribs,  but  Dr.  Wollemanii 
informs  nie  that  that  character  is  variable.  1  have  sent  a  specimen  from  the 
(Jlaxby  Ironstone  to  Dr.  AVollemann,  and  he  is  able  to  confirm  my  identification  of 
the  species.  Specimens  from  the  Spoeton  Clay  ilit'fei'  from  those  found  in  Liueuln- 
shire  in  haviiii;-  fewer  i'il)s  w  itli  relatively  fewer  grooves,  but  since  this  is  a  very 
variable  character  it  cannot  be  regarded  as  indicative  of  more  than  a  local  variet}-. 


Fill.  ;i.— iimri  (I'Uujiosloma)  subri<jida,  Kiimor.     Claxby  Ironstoui!,  Buuuiwurth  Uiivuu.     Arua  of  ri^'lit 

valve.      X  |.     Sedgwick  Museum. 

Ti/jir.'i. — Fi'om  the  Ililstlion  of  Hrunswiek. 

Ihslriliiiflmi. — Cla.\1)y  Ironstone  (zone  of  Ih'lcianitcs  Idteralts)   of    iJenuiwortli 
Haven.      Upper  |)art  of  the  SiJeeton  Clay  of  Speeton. 


Lima  (I^.aciostoma),  sp.  cf.  Okukjnya.va,  MutluToii,  181-2.     Plate  III,  figs.  10,  n — c. 

1812.     Lima  Ukbignyana,  P.  Mullwron.    Cat.  Foss.  dcs.  Bouclies-du-Rhone,  p.  182, 

pi.  xxi.\,  fij,'s.  3,  4. 

1846.       —  —  A.  d'Orbiijiuj.     Pal.  Frauy.  Terr.  Cn't.,  vol.  iii,  p.  530, 

pi.  ccccxv,  figs.  1 — 4. 

1860.        —  —  d'Orhhjnij.      Prodr.  do  Pal.,  vol,  ii,  p.  lU7. 

18.55.       —  —  G.  Cotteau.     Moll.  Foss.  de  rVoiiue,  y.  lUU. 

1865.  —  —  H.  Coqitand.     Mou.  Aptk-ii  do  rFsjia','!!!',  p.  IlK. 

1866.  -^  —  P.  de  Loriol.     Foss.  O.^litli.  Corall.  V-aliiw^.  ct   Vf^«n. 

Mt.  SuIlvo,  p.  82,  pi.  D,  fii^r.  13. 

1867.  —  —  de  Luriul,  iu  Favrc.      liecL.   ycol.   Saus  Savoie,  vol.   i, 

p.  387,  pi.  C,  fiy.  24. 
1869.       —  —  F.  J.  I'ictfl  and  G.  Campiche.     Foss.  Terr.  Crct.  Ste. 

Oroi,\  (Mater.  Pal.  Suisse,  ser.  6), 
p.  126,  pi.  cLxi,  fiy.  4. 
1871.     IvADULA  (Acesta)  Obbionyana,  F.  SluiiczJca.    PalaDout.  Indica,  Cret.  Fauua 

S.  ludia,  vol.  iii,  p.  414. 

1  Loc.  cit.,  p.  140,  i>I.  clxiv,  figs.  1,  2. 


LIMA.  13 

Description. — Sliell  moderately  convex,  oval,  liit^licr  than  long,  venti-al  and 
posterior  margin  rounded.  Umbone.s  sharp.  Apical  angle  about  80°.  Anterior 
area  depressed,  limited  by  a  rounded  edge,  ornamented  with  riljs.  Ears  with 
distinct  growth-ridges.  Posterior  ear  higher  than  hnig,  and  larger  than  the 
anterior  ear. 

Ornamentation  consists  of  about  52  flattened  ribs,  slightly  undulating, 
separated  by  very  nari-ow  grooves  Avitli  pits.  Near  the  ventral  margin  the  ribs 
become  divided  by  a  median  groove.  Near  the  anterior  and  posterior  margins 
the  ribs  are  rather  narrower  than  elsewhere.  A  few  moderately  distinct  growth- 
lines  occur. 

Measurements  : 

Length        ....  20     mm. 

Height         ....  25-5     „ 

-Ufiiiitics. — This  is  distinguished  from  L.  rillerseiisis  (see  below)  by  its  more 
numerous  and  narrower  ribs. 

Remark. — I  have  seen  one  specimen  only,  which  is  preserved  in  the  British 
Museum,  No.  L  157-ji. 

Didrihnfiiiii. — Lower  Greensand  (Ferruginous  Sands)  of  Shanklin. 


LiM.v  (Plagiostojia)  viLLiousKNsis?  I'ictct  uiul  Cuiiijuclu',  18G'J.     i'lale  ill,  ligs.  Ihi, 

Ul>,l2<i,b,r3. 

?  1869.     Lima  villersensis,  F.  J.  Pictet  and  G.   Campiche.      Foss.  Terr.  Crt't.  Ste. 

Croix  (Mati'r.  Pal.  Suisse,  ser.  5), 
pp.  127,  162,  pi.  clxi,  fig.  5. 

Description. — Shell  moderately  convex,  oval,  higher  than  long,  ventral  and 
posterior  margins  rounded.  Umbones  sharp.  Apical  angle  about  8-5°.  Anterior 
area  depressed,  bounded  by  a  sharp  edge.  Posterior  ear  larger  than  the  anterior, 
higher  than  long,  with  the  outer  angle  obtuse,  and  with  a  few  radial  ribs. 

Ui'nameutation  consists  of  from  o2  to  ^G  broad,  flattened,  nearly  straight  ribs, 
separated  by  linear  grooves  with  distinct  pits.  Near  the  anterior,  and  sometimes 
near  the  posterior  border,  the  riljs  l)econie  narrower.  A  few  well-marked  growth- 
ridges  may  occur  at  distant  intervals.  Near  the  ventral  mai-gin  of  the  valves 
(ventral  to  a  growth-ridge)  the  position  of  the  ribs  is  sometimes  slightly  shifted, 
and  the  number  of  ribs  may  increase  owing  to  the  fission  of  some. 

Measurements  : 

(1)  (2)  (3)  (4) 

Length   .  20  .  10  .  18  .  II  nun. 

Height   .  2G-.J      .         2.5  22         .         17    „ 

(1 — 4)  Lower  GreeusauJ,  i'ariugJou. 


II  CRETACEOUS   LAMELT.TBK.WCTTT A. 

Affinilu's. — I  have  seen  only  a  few  examples  of  this  form.  They  agree  witli 
L.  viUerseims  except  in  having  a  rather  smaller  apical  angle.  In  this  respect  they 
resemble  L.  Orhifjnydna,  Matheron  (see  above),  but  tliey  differ  from  that  species  in 
possessing  fewer  and  straighter  ribs.  I  have  not  seen  any  undoubted  example  of 
L.  vUlcrscniyis  and  am  nnal)lc  to  state  whether  the  apical  angle  is  constantly  larger 
than  in  the  English  si)ecimens.  Pictet  and  Campiche  say  that  it  is  about  95°,  but 
the  specimen  they  figure  possesses  an  apical  angle  of  90°  only.  In  the  English 
specimens  it  is  about  85°. 

This  is  the  form  which  was  referred  by  Sharpe^  to  L.  coiisoliriim,  d'Orbiguy, 
but  it  possesses  considerably  fewer  riljs  than  that  species. 

Ti/pe. — L.  villersemk  is  found  in  the  Valanginian  of  Ste.  Croix. 

Dlddbidion. — Lower  Greensand  of  Fariugdon. 


Lima  (1'i,A(J1u,stu.ma)  tiKmoii^xiWjifOjiiiyiiij,  lb  1-7.      Plate  III,  figs.   11,   15,   10",//. 

Plate  IV,  fig.  1. 

1847.     Lima  semioenata,  A.  d'Orhujuy.     Pal.  Fran9.  Terr.  Crct.,  vol.   iii,  p.  555, 

pi.  ccccxxii,  figs.  1 — 3. 
1850.       —  —  d'Orhlijnij.     Prodr.  de  Pal,  vol.  ii,  p.  167. 

18(37.       —  —  E.    Gue'raiujer.     Album    Pak'out.    de    la    Sartlio,   p.    19, 

pi.  xxiv,  &g.  13. 

1870.  —  —  F.  J.   Fidel  and  G.   Campiche.     Foss.  Terr.   Crt't.  Ste. 

Croix   (Mater.    Pal.   Suisse,  ser.   6), 
p.  169. 

1871.  Radula  (Plagiostoma)  semioenata,  F.  Stoliczka.     Palseout.  ludica,  Cret. 

Fauna  S.  India,  vol.  iii,  p.  414. 
?  1885.  —  —  —  F.  Niitling.     Die  Fauna  d.  Laltisch. 

Cenomau.  (PalsBont.  Abhandl., 
vol.  ii),  p.  15,  pi.  ii,  fig.  4. 

description. — Shell  compressed,  rounded,  lieight  and  length  nearly  equal. 
Antei'o-dorsal  border  straight  or  slightly  concave.  Umbones  close  together. 
Anterior  area  depressed,  with  a  sharp  edge.     Apical  angle  120°. 

Surface  nearly  smooth,  shiny,  with  numerous,  very  fine,  regular,  concentric 
linear  ridges,  and  with  radial  punctate  grooves  near  the  umbo  and  near  the 
anterior  and  posterior  margins.  The  grooves  near  the  anterior  margin  are  fewer 
and  more  widely  separated  than  those  near  the  posterior  margin. 

'  '  Quai-t.  Jouru.  Geol.  Soc.,'  vol.  x  (1853),  p.  193  (snh-consobrina,  d'Orbigny,  'Prodr.  de  Palcont.,' 
(1850),  p.  167). 


LIMA. 


15 


Mensnrcmrrifs 


Length 
Height 


(5) 

23  mill. 
23    „ 


(1)  (2)  (3)  (4) 

32  .         31         .         29         .         29         . 

33  .         32         .         29         .         26 
(1,  2)  Upper  Grecnsand,  Potterne. 

(3,  5)      „  „  Ventnor. 

(4)      „  „  Blackdown. 

Affi.nitics. — This  species  is  distinguished  by  its  compressed  valves  and  rouiulcd 
outline. 

Tijpe. — From  the  Cenomaniau  of  Le  Mans. 

Distribution. — Upper  Greensand  (zone  of  Schlmnhachia  rostniln)  of  Potterne 
(Devizes)  and  Blackdown.  LTpper  Greensand  (zone  of  Feet  en  asper)  of  Ventnor. 
Chalk  ]\Iarl  of  Folkestone. 


Lima  (Plagiostoma)  Meteri,  sp.  nov.     Plate  IV,  figs.  2,3.     Text-fig.  4. 

1896.     Lima  simplex,  A.  J.  Jukes-Browne.     Quart.  Joum.  Geol.  Soc,  vol.  lii,  p.  162. 

Description. — Shell  ovate  or  subtrigonal,  much  compressed,  a  little  higher  than 
long,     oblique,     considerably     inequilateral ;     antero-dorsal     margin     long    and 


Fio.  4. — Lima  (Plagiostoma)  Meyeri,  sp.  nov.     Upper  Greensand,  Warminster.     Museum  of  Practical  Gcologj-, 
No.  8838.     Left  valve  and  antero-dorsal  view.     Natural  size. 

straightened,  ventral  and  postero-ventral  margins  rounded.  Umbones  small,  close 
together.  Ajiical  angle  from  90°  to  100°.  Anterior  area  depressed,  long  and 
narrow,  with  a  few  radial  7-il)s  and  vertical  grooves.  Posterior  ear  small  ;  anterior 
ear  not  seen. 

Ornamentation  consists  of  narrow,  linear,  .-^hallow,   pitted  grooves  wliieli  may 


(3) 

(4) 

(5) 

48 

42       , 

34  mm 

52 

47       . 

37    „ 

16  CRETACEOUS   LAMELTJBR AXCTITA. 

be  confined  to  tlio  anterior  and    posterioi-  ])arts  of  the  valves  or  ina_y  extend  over 
the  whole  surface.     The  grooves  are  soniewliat  irreG^nlar  aiid  tlie  interspaces  are 
broad  and  flattened.     At  distant  intervals   a   few  well-inarked  Ljrowtli-riniifs  occnr, 
l)cyond  -which,  in  some  cases,  the  iil)s  cease. 
Arf'anirrrmfvfs  : 

(I)  (2) 

Length      .       (\9         .         53 

Height      .      71  .         5G 

(1 — .5)  Uppov  GrociisaiKl,  Wariiiiiistor. 

Affivifici. — This  species  differs  from  Li'ma  armhivuKfn  (p.  1  1)  in  lieing  larger, 
relatively  higher,  more  trigonal  in  outline,  and  in  having  tlie  I'adial  grooves  nmi'c 
extensively  developed.  It  is  distingnisheil  fi'oni  Lhiiit  sin/jih-.r,  (l"()i'l)igny,'  in 
being  nnicli  less  convex,  in  the  height  being  relativel}'  less,  the  antei-o-dorsal 
margin  shorter,  the  anterior  area  smaller,  and  the  anterior  grooves  less  })rominent. 

The  shell  is  relatively  longer  and  the  apical  angle  larger  than  in  L.  siiJi-rnvfto- 
Iniiiii,  d'Orbigny."  It  is  also  relatively  longer,  Avith  a  longer  antero-dorsul  nuirgin 
and  the  radial  grooves  less  well  developed,  than  in  L.  nrtumi  (p.  22). 

Tijix'n. — From  Warminster.     In  the  Museum  of  Practical  Geology. 

Dinfribitfinn. — Upper  Grecnsand  (zone  of  Ppc/pu  asppr)  of  Warminster.  Eye 
Hill  Sands  and  Chloritic  Marl  of  Maiden  Bradley.  Cennmaninn  flMeyer's  Beds  10 
and  11)  of  Hooken  and  Dunscombe  (Devon  coast). 


liLMA   (l'l..\i;insTnMA)  (il.olinSA   {Si)irri-h//),   \H'A(>.      I'llltc  I  \\  flgS.  4w^ — C,  hilji,  i't  (I — C. 

183G.     LuciNA?  Gi.oBosA,  J.  (}('  C.   Sowrhi/.     Tiaus.   GphI.   Soe.,  ser.  2,  vol.  iv, 

p.  335,  pi.  xi,  fig.  2  (non  Lucimi 
ylohosa,  Riimer,  1839). 

1854.     Lima  (iLODosA.     J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  171. 

1895.        —         —  E.   Tiessen.     Zeitschr.   iI.t  dcuts.li.   l;oi.1.   Oosfllsili.,   v..l 

.\lvii,  ]).  473. 

Descrijitioii. — Shell  very  convex,  of  moderate  size,  oval,  length  considei'ably 
greater  than  height,  outline  rounded  with  the  nntero-dorsal  margin  long  and 
straightened.  Umbones  incurved,  bhint.  Apical  angle  al)out  11S\  Anterioi' 
area  large,  very  deep,  limited  by  a  sharj)  edge,  with  ratUal  i-ibs.     Ears  small. 

S\irface   of    v.alves    polished,   with    faintly-marked    growth-lines    at    intervals; 

'  'Pal.  Fi-au^.  Terr.  Crct.,'  vol.  iii  (1847),  p.  545,  pi.  ccccxviii,  fijrs.  6—7. 

-  Il)id.,  p.  55G,  pi.  ccccxxii,  figs.  4 — 7;  L.  »uh-consohrinii,  d"Orl)igny,  '  Prodr.  de  Palcont.,'  vol.  ii 
(1850),  p.  167. 


LIMA.  17 

ornamented  with  numerous  pits  having  a  regular  radial  and  concentric  arrange- 
ment and  giving  rise  (in  some  cases)  to  the  appearance  of  slightly-raised  radial 
and  concentric  ribs.  Near  the  ventral  margin  the  pits  become  more  elongated 
(parallel  with  the  margin)  and  their  concentric  arrangement  may  become  wavy  or 
irregular.  At  the  anterior  and  posterior  margins  the  radial  arrangement  is  often 
more  distinct  than  elsewhere.  Sometimes  on  the  median  ])art  of  the  valve  the 
concentric  arrangement  alone  can  be  recognised. 
Measurements  : 

(1)  (2)  (3)  (i)  (5) 

Lent^th    .     31     .     27     .     25     .     24     .     22 


«^) 

(7) 

(H) 

20     . 

18     , 

12  mm. 

17     , 

,     K)     , 

.     10     „ 

Height     .     25     .     23     .     21     .     21     .     19 

(1—3,  5,  7,  8)  Tottemhoe  Stoue,  Bunvell. 
(4)  Chalk  Marl,  Veutuor. 
(6)       ,,         ,,      Clevancy. 

Affinities. — This  species  closely  resembles  Lima  albensis,  d'Orbigny/  from  the 
Gault  of  Ervy  (Aube),  Macheromenil  (Ardennes),  the  Perte-du-Rhone,  etc.  I  have 
not  seen  any  specimens  of  L.  albent^ls,  but  it  appears  to  differ  from  //.  glfiljosa  in  the 
absence  of  the  punctate  ornamentation  and  in  having  a  smaller  apical  angle. 

L.  (jlohosa  is  distinguished  from  L.  Hoperl  (see  below)  by  its  smaller  size,  more 
intiated  valves,  and  by  the  close-set  rows  of  radial  and  concentric  pits. 

Type. — In  the  Museum  of  the  Geological  Society,  No.  1538,  from  the  Chloritic 
Marl  of  the  Isle  of  Wight. 

Distribution. — Gault  of  Folkestone.  Red  Limestone  of  Ilunstaaiton.  Upper 
Greensand  of  Warminster.  Cambridge  Greensand  (base  of  Chalk  Marl).  Chalk 
Marl  of  Ventnor,  Clevancy,  Chilcomb  well  (Winchester),  Burham,  Folkestone  and 
Cherry  Hinton.  Cenomanian  of  Wilmington.  Totternlioe  Stone  of  Burwell. 
Zone  of  H.  subylobosus  of  Chilcomb  and  Fulbourn. 


Lima  (Plagiostoma)  lloi'uui,  Mantell,  1822.      Plate  IV,   figs.  7,  Sa,  l>,  \hi,  l>,  10, 

11((,  /;,  12a,  b. 

1822.    Plagiostoma  Hopeei,    G.   Mantell.      Foss.   S.   Dowus,  p.  20-i.  pi.  xxvi. 

figs.  2,  3.  15. 
—  _  —         /.  de  €■  Sowerhij.     Min.  Couch.,  vol.  iv,  p.    ill. 

pi.  ccckxx. 


1  'Pal.  Fran?.  Terr.  Crct.,'  vol.  iii  (1847),  p.  541,  pi.  cceexvi,  figs.  1-5,  IG ;  '  Prodr.  de  Palcont.,' 
vol.  ii  (1850),  p.  138 ;  Pictet  aud  Roux,  '  Moll.  Foss.  Grcs  verts  de  Geuivc  '  (1852),  p.  488,  pi.  xl, 
tig.  9;   Pictet  aud  Campiche,  "  Poss.  Terr.  Crct.  Ste.  Croix"  (' Mat^'r.   Pal.    Suisse.'  ser.  5.  18(3'.'). 

p.  160. 

o 


18  CRETAGEOUS   LAMELLIBRANCHIA. 

1822.     Plagiostoma  Mantelli,  A.  Brongniart.     Descript.  gcol.  euvir.  de  Paris. 

In  Cuviers  Ossem.  Foss.,  vol.ii, 
pt.  2,  p.  GOO,  pi.  iv,  fig.  3. 
1825.     Pachytos  Hopeei,  M.  J.  L.  Defmnce.     Diet.  Sci.  nat.,  vol.  xxxvii,  p.  207. 
1827.     Plagiostoma  punctatum,  S.  Nilsson.     Petrif.  Suecana,  p.  24,  pi.  ix,  fig.  1. 
1832.     Lima  Hopeei,  G.  P.  Deshayes.     Iii  J.   G.  Bnujuirre,  Hist.  nat.  des  Vers  et 

des  Moll.  (Eucyc.  lUL'thod.),  vol.  ii,p.  349. 

1836.  —    Mantellii,  A.  Goldfuss.     Petref.  Grerm.,  vol.  ii,  p.  92,  pi.  civ,  fig.  9. 

—  —     HoPEKi,  Goldfuss.     Ibid.,  p.  91,  pi.  civ,  fig.  8. 

—  —        —        Lamarck.     Aniiii.  saus  Vert.  (ed.  2  by  Deshayes  and  Milne- 

Edwards),  vol.  vii,  p.  120. 

1837.  Plagiostoma  punctatum,  W.  Hisinger.     Lethsea  Suecica,  p.  54  {not  pi.  xv. 

fig.  3). 

1838.  Lima  Hopeei,  H.  G.  Bronn.  Lethsea  Geognost.,  vol.  ii,  p.  682,  pi.  xxxii,  fig.  8. 

1839.  —         —        H.    B.    Geinitz.       Char.    d.    Schicht.    u.    Petref.    des  siichs. 

Kreidegeb.,  pt.  1,  p.  24  {?  parti m). 

1841.  —     'HahtbIiIjU,  F.  A.  Earner.     Die  Versteiu.  d.  uord-deutsch.  Kreidegeb., 

p.  58. 

—  —     Hopeei,  Bomer.     Ibid.,  p.  58. 

—  —     NiLSSONi,  Burner.     Ibid.,  p.  57. 

1842.  —     GoLDFUssi,  F.  v.  Hagenow.     Neues  Juhrb.  fiir  Miu.,  etc.,  p.  555. 

?  1846.        —     Mantelli,  H.  B.  Geinitz.     Grundr.  d.  Versteiu.,  p.  472,  pi.  xx,  fig.  13. 

—  —     Hopeei,  Geinitz.     Ibid.,  p.  473,  pi.  xx,  fig.  14. 

—  —        —        A.  E.  Beuss.     Die  Versteiu.  der  bohm.  Kreidefomiat.,  pt.  2, 

p.  34,  pi.  xxxviii,  figs.  11,  12. 
1847.        —     So-wvu-DYi,  J.  Mailer.     Petref.  der  Aachen.  Kreidef.,  pt.  2,  p.  67. 
1850.        —     Hopeei,    H.   B.    Geinitz.      Das   Quadersaudst.    oder    Kreidegeb.    iu 

Deutschland,  p.  192. 

—  —     SowEEBYi,  Geinitz.     Ibid.,  p.  192. 

—  —     Hopeei,  A.  Alth.     Geogn.-jialaiont.  Beschreib.  von  Lemborg  (Haidiu- 

ger's  Naturwiss.  Abhandl.,  vol.  iii,  pt.  2),  p.  240. 
?    —  —     Mantelli,  Ii.   Kiier.      Verstein.    v.    Lemberg    (Haicliuger"s    Natur- 

wissensch.  Abhandl.,  vol.  iii,  pt.  2),  p.  29. 
Plagiostoma  Hopeei,  var.,  /.  de  0.  Sowerhj,  in  F.  Dixun.     Geol.   Sussex, 

pp.  348,  356  (p.  383,  ed.  2), 
pi.  xxviii,  fig.  21. 
1851-2.     Lima  Soweebyi,  H.  G.  Bronn.     Lethsea  Geogn.,  ed.  3,  vol.  ii,  pt.  5,  p.  278, 

pi.  xxxii,  fig.  8. 
?  1852.       —     Hopeei,  R.  Kner.     Deukschr.  d.  k.  Akad.  d.  Wissensch.  Wieu,  Math.- 

nat.  CI.,  vol.  iii,  p.  318. 
1854.       —        —        J.Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  171  (^«n-/(«0. 
1863.       —        —        S.  Placketko.     Das  Becken  von  Lemberg  (Jahresber.  d.  k.  k. 

zweit. Ober-gymuas.  iu  Lemberg,  1863). p.  I'.t. 

—  —         —         A.  von  Slrombeck.      Zeitsohr.  d.    deutsch.   geol.  Gesellsch., 

vol.  xv,  p.  148. 

—  —         —         B.  Drescher.     Ibid.,  p.  355. 

1869.        -■  -         E.   Favre.      Moll.   Foss.  de  la  Craie  de  Lemberg,  p.   137, 

pi.  xii.  fig.  19. 


LIMA.  19 

1870.     Lima  Hoperi,  F.  Eiimer.     Geol.  von  Oterscliles.,  p.  315,  pi.  xxxiv,  R^.  10. 

—  —  —F.J.  Fidel  and  G.  Caminche.     Foss.  Ten-.  Crct.  Sfo.  Croix 

(Mati'r  Pal.  Suisse,  ser.  5), 
pp.  171,  173. 

—  —     SowEKBYi,  Pictet  and  Campiche.     Ibid.,  p.  173. 

187'2.       —  —  H.   B.  Geinitz.     Das  Elbtlialgeb.   in  Sachscn  (Palaeonto- 

graphica,  vol.  xx,  pt.  2),  p.  41,  pi.  ix, 
figs.  13,  14. 

1877.       —  —  A.  Frit  sell.     Stud,   im  Gebiete  dev  bijlini.  Kreideformat. : 

II,  Weissenberg.     u.     Malnitz.      Schicht., 
p.  133,  fig.  120. 

1882.  —     HoPEEi,   H.   Schrikler.     Zeitsclir.  der  deiitsch.   geol.   Gesellsch.,  vol. 

xxxiv,  p.  263. 

1883.  —     SowEEBTi,  A.  Fritsch.    Stud,  im  Gebiete  der  l)61iin.  Kreideformat.: 

III,  Iserscbiclit.,  p.  115,  fig.  87. 

1888.  —     HoPEEi,  ^.  Pew).     L'Hist.  Terr,  de  Craie,  p.  149. 

1889.  —     (Plagiostoma)  Hopeki.      0.    Griepenkerl.      Senon.  v.  Ktinigslutter 

(Palseont.  Abliaudl.,  vol.  iv), 
p.  40. 

—  —     HopEKi,  A.  Fritsch.     Stud,  im   Gebiete  der  biihm.   Kreideformat.: 

IV,  Teplitz.  Seliiclit.,  p.  84,  fig.  78. 

—  —         —         E.  Hohapfel.     Die  Mollusk.  Aaclien.  Kreide   (Palaeontogra- 

pliica,  vol.  xxxv),  p.  240,  pi.  xxvii,  fig.  5. 

1892.  —     (Plagicstoma)  Hopeei,  E.  Stolley.     Die  Kreide  Sehleswig-Holsteins 

(Mittbeil.  a.  d.  Mineralog.  Instit. 
Univ.  Kiel,  vol.  i),  p.  237. 

1893.  —     HopERT,  A.  Frit. fcJi.     Stud,  im  Gebiete  der  bohm.  Kreideformat. :  V, 

Priesener  Schicht.,  p.  100. 

1894.  —         —         B.  Lundgren.       Mollusk.    i   MammiUatus-   ocli   Miicronata- 

zonerna  (K.  Svenska  Vet.  Akad.  Handl. 
N.  F.,  vol.  sxvi,  No.  G),  p.  42. 

1897.  —         —        B.  Leonhard.       Kreideformat.    in    Olierschles.    (Palaconto- 

graphica,  vol.  xliv),  p.  46. 

—  —         —         A.  Hetinifj.    Eevis.  Lamellibr.  i  Nilsson's  '  Petrifie.  Suecana,' 

(K.  Fysiogr.  Siillsk.  i  Lund.  Handl.,  N.  F., 
vol.  viii),  p.  30,  pi.  ii,  fig.  13. 

—  —     (Plagiostoma)  Hoperi,  H.  Woods.    Quart.  Journ.  Geol.  Soc,  vol.  liii, 

p.  383. 

1898.  —     Hopeki,  G.  Miiller.     Mollusk.  Untersen.  v.  Braunschweig  u.  Ilsede, 

p.  24,  pi.  iv,  fig.  1-2. 

1901.  —         —        A.  Wollemann.     Jahrb.  d.  k.  preussisch.  geol.  Landesanst. 

fiir  1900,  vol.  xxi,  p.  15. 

1902.  —        —        A.  WoUemann.    Liineburg.  Kreide  (Abhandl.  d.  k.  preussisch. 

geol.  Landesanst.,  N.  F.,  Heft  37),  p.  58. 

_.  —         J.  P.  J.  Ram.    Mollusk.  Danmarks  Kridtaflej.  :  I,  Lamellibr. 

(K.  Danske   Vid.  Selsk.  Skrift.  6  Rtekko, 
nat.  og  math.  Afd.,  vol.  xi),  p.  99,   pi.   ii 
fit;.  18. 


20  CRETACEOUS    LAMELLIBRANCHIA. 

Non  1847.       —         —         A.  iT  Orhiyny.     Pal.  Franc.   TeiT.   Cret.,  vol.  iii,  p.   .'JC4,  pi. 

ccccxxiv,  figs.  10 — 13. 
1847.       —     Mantelli,  (VOrhigny.     Ibid.,  p.  568,  pi.  ccccxxvi,  figs.  3 — 5. 

—  18-50.       —     HoPEEi,  d'Orhujny.     Prodr.  de  Pal.,  vol.  ii,  p.  248. 

—  —  —     Mantelli,  cTOrhigny.     Ibid.,  p.  248. 

1877.       —     HopERi,  A.  FritscJi.     Stud,  im  Gebiete  der   bijhm.    Kreideformat. : 

II,  Weisseuberg.  u.  Malnitz.  Schielit.,  p.  134, 
fig.  121. 

—  —  —     Mantelli,  Fritsch.     Ibid.,  p.  134,  fig.  122. 

—  1872.       —     HoPEEi,   H.  B.  Gcinitz.      Das   Elbthalg<>l>.    in    SacLsen    (Palaonto- 

graphica,  vol.  xx,  pt.   2),  p.  40,  pi.  ix, 
figs.  11,  12. 

—  1881.       —         —         J-   Kiesow.      Cenomanversteiu.   a.    d.   Diluvium   d.   Umgeg. 

Danzig's    (Schrift   d.   naturf.    Gesellseb.    in 
Danzig,  N.  P.,  vol.  v),  p.  414,  figs.  9,  10. 
?   —     1893.       —     sp.,  cf.  HopERi,  B.  Michael      Zeitschr.  d.  deutscb.  geol.  Gesellsch., 

vol.  xlv,  p.  234. 

Descrijitiou. — Shell  convex,  oval,  rounded,  considerably  inequilateral,  longer 
tlian  high.  Antero-dorsal  margin  rather  long,  slightly  convex  or  nearly  straight ; 
postero-dorsal  margin  rather  short ;  the  remainder  forming  a  regular  curve. 
Umbones  close  together.  Apical  angle  115°  to  117°.  Ears  rather  small,  with 
growth-lines;  the  posterior  longer  than  high  and  larger  than  the  anterior  ear. 
Anterior  area  large,  deep,  with  a  more  or  less  sharp  border,  often  with  radial 
grooves  which  vary  in  number  and  are  more  distinct  near  the  umbo  than 
anteriorly. 

Surface  of  shell  nearly  smooth.  In  the  region  of  the  umbo  numerous  linear 
grooves  with  pits  occur ;  these  may  also  extend  on  to  the  anterior  and  posterior 
parts  of  the  shell,  and  in  some  cases  they  are  present  on  the  middle  of  shell, 
reaching  a  part  of  the  way  or  even  quite  to  the  ventral  margin.  The  grooves  are 
slightly  wavy,  sometimes  discontinuous,  and  are  deeper  near  the  anterior  and 
posterior  margins,  and  often  more  widely  separated  near  the  former.  'New 
grooves  are  introduced  at  various  distances  from  the  umbo. 

Measurements  : 

(1)        (2)        (3)        (4)        (5)        (6) 

Length     57     57     56     52     51     51 
Height     52     50     52     50     47     40 

(1)  M.  cor-anguimini  zone,  Graveseiid. 

(2)  Uintacrinus   band,    Devizes    Road, 

Salisbury. 
(3,  6,  12)  A.  quadratus  zone.  East  Harnbam. 
(4,  7)  M.  cor-anguinum  zone,  Gravesend. 


(7) 

(8) 

(9) 

(10) 

(11) 

(12) 

47 

41 

37 

34 

31 

31  mm. 

42 

39 

32 

32 

28 

26  „ 

(.5,  10)  M.  cor-anguinum  zone,  Northflcet. 
(8)  Chalk  Rock,  Underwood    Hull,   Dulliii 
bam. 
(9,  11)  B.  mucronata  zone,  Norwich. 


Affinities. — This  species  was  described  by  Brongniart  under  the  name  ri(i<jios- 
tnnia    Miiiif'-lli  from    spccimeTis    wliich    wore   sent   to  him   by   Mantcll  from    near 


LIMA.  21 

Brighton— probablj'  from  Lewes.  Maiitell '  regarded  Plafiiostoma  Mtintelli  as  a, 
synonym  of  his  riat/iosfomn  Ifupi'n,  and  I  think  there  can  lie  no  doubt  as  to  the 
correctness  of  that  view. 

Geinitz  (1872)  considered  Lima  Hoperi  of  Sowerby  to  be  distinct  fromL.  lloperi 
of  Mantell,  thinking  that  the  former  (which  he  named  L.  Son-erbi/i)  was  distinguished 
by  being  almost  smooth,  whereas  the  latter  is  covered  with  radial  grooves.  The 
smooth  and  the  gi'ooved  forms  agree  exactly  in  shape,  and  between  these  extremes 
in  ornamentation  every  gradation  may  be  seen.  Moreover,  although  one  of  the 
specimens  figured  by  Mantell  (fig.  3)  is  ornamented  all  over,  the  others  (figs.  2,  1 5) 
possess  grooves  on  the  sides  only.  I  think,  therefore,  that  there  can  be  no  doubt  as 
to  the  identity  of  L.  Hoperi  of  Sowerby  and  L.  Ilopori  of  Mantell.  Further,  it 
should  be  noted  that  Sowerby's  specimens  were  sent  to  him  by  ]\Iantcll  as  examples 
of  his  L.  Hopori. 

The  specimens  figured  h\  Geinitz  (1872)  as  L.  Ilopcri  (from  the  Pliiner-kalk  of 
Strehlen)  are  relatively  higher  (especially  fig.  11)  than  Mant ell's  species,  and  are 
probably  examples  of  L.  crefacm  (see  below). 

L.  Ropcrl  of  d'Orbigny-  differs  in  having  a  smaller  apical  angle,  in  being 
relatively  higher,  much  compressed,  and  with  the  grooves  more  widely  separated. 
It  may,  however,  be  only  a  variety  of  L.  Hoperi,  Mantell.  I  have  seen  undoubted 
examples  of  L.  Hoperi,  Mantell,  from  the  Senonian  of  Marromme  (near  Rouen), 
Lillebonne  (Seine-Inferieure),  and  from  other  French  localities.  The  form  de- 
scribed and  figured  l)y  d'Orbigny  as  L.  MantcJU  is  referred  to  below  (p.  2o). 

L.  Lamberti  of  Peron,'  fi'om  the  zone  of  Micraster  breviporus  of  Joigny,  may  be 
only  a  variety  of  L.  Hoperi.  It  is  stated  to  diifer  chiefl}'  in  its  greater  length,  but 
in  this  respect  it  can,  I  think,  be  matched  by  some  undoubted  varieties  of  L. 
Hoperi. 

For  the  relation  of  L.  Hoperi  to  Z.  ijlobosa  see  page  17,  and  to  L.  cretacea 
see  page  23. 

Bemarhs. — This  species  varies  considerably  in  the  extent  of  the  ornamentation. 
Some  examples  are  smooth,  save  for  the  pitted  grooves  near  the  umbo ;  in  many 
cases  the  grooves  are  continued  on  to  the  sides  of  the  sliell ;  less  frequently  they 
extend  to  the  middle  of  the  valve,  and  may  even  reach  the  ventral  margin.  I 
have  not  seen  sufficient  examples,  of  which  the  exact  liorizons  are  known,  to  enable 
me  to  determine  whether  any  of  the  varieties  are  characteristic  of  certain  zones. 

Types. — I  have  not  seen  the  types.  The  specimens  figured  by  Sowerby  are  in 
the  British  Museum.  The  types,  and  also  Sowerby's  specimens,  came  from  the 
Upper  Chalk  (probably  from  the  zone  of  Micraster  cor-testudinarium  or  the  zone  of 

•  'Trans.  Geol.  Soc.,'  ser.  2,  vol.  iii  (1835).  p.  206. 

"-  See  Jukes-Browne,  'Quart.  Jouru.  Geol.  Soc..'  vol.  Iii  fl89(!).  p.  152. 

8  '  Hist.  Terr.  <!»>  Craie '  (1888),  p.  151.  pi.  ii.  fi.,'.  1. 


22  CRETACEOUS   LAJVIELLIBRAKCHIA. 

M.  cor-mujuimim)  near  Lewes.  An  example  from  Cambrai  is  in  the  d'Orbigny 
Collection  at  Paris,  but  it  is  probably  not  the  specimen  figured  in  the  '  Palcontologie 
Fran^aise.' 

Disfrihnfidii. — (i)  Zone  of  Tcrehraiulina  of  Bevendean,  near  Brighton.' 

(ii)  Zniip  of  IfoJiisfrr  pltiinis-  of  AVinehester,  Lewes,  Dovei',  Kcnl(>y,  Ciixton. 
Chalk  Rock  of  Boxnioor,  Luton,  Underwood  Hall  (DuUinghani),  Westley 
Waterless. 

(iii)  Zone  of  Micrastrr  (■(>r-lc-'<fii(liii«(rivm  of  Lewes,  Dover,  Purley,  Strood, 
Chatham,  Swaffham-  (Norfolk). 

(iv)  Zone  of  Micr<nter  cor-anr/uimnn  of  Winchester,  Porton,  AVitherington, 
Qnidhampton,  Lewes,  the  Sussex  coast,  St.  Margaret's,  Gravesend,  Northflect, 
Hailing  Pit  (South  Croydon). 

(v)  Zone  of  Marsupifcs  tefffndwariiis  of  the  coasts  of  Sussex,  Thanct,  and 
Yorkshire.      T^iutacniiiis  hnml  of  Devizes  Road,  Salisbury. 

(vi)  Zone  of  Arfiuocamax  <jii<nhrihii<  of  East  Harnham,  Hurslcy  (Winchester), 
the  coasts  of  Sussex  and  Yorkshire. 

(vii)   Zone  of  Bi-lmniifiila  mvcrovafa  of  the  Dorset  coast  and  Norwich. 

(viii)  ('lialk  of  Trimingham. 


JiiMA  (Pi.a(!I(»stiima)  ciiKTACEA,  uoiu.  uov.     Plate  IV,  figs.  13,  14  (I — r',  15.    Plate  V, 

figs.  \(i,h,  2,  o,  A«,h. 

?  1847.     Lima  Mantei.i.ii,  A.  (VOrhujnu.     V-A.  Fraii9.  Terr.  Crt't.,  vol.  iii,  ji.   508, 

pi.  ccccxxvi,  figs.  3 — 5   (uou  L.    Man- 
telli,  Brongniart). 

V  1850.       —  —  —  Prodr.  de  Pal,  vol.  ii,  p.  248. 

—  —      L.s:viuscuLA,  J.  de  C.  Sowcrhy,  in  F.  Dixon.     Geol.   Sussex,  p.  347 

(p.  382,  ed.  2),  pi.  xxviii,  fig.  14, 
(uou    L.    Ireviuscvla,     Sovcerby, 
1822). 
y  1872.       —      HorEKi,  H.  B.  Geinitz.     Das  Elbthalgeb.  iu  Sachseu  (Palaeontogra- 

jilupa,  vol.  XX,  pt.  2),  p.  40,  pi.  ix,  figs.  11,12. 
?  1877.       —  —        A.  Frxtsch.     Stud,  iiu  Gebiete  der  buhm.  Kreidoformat.  :  II, 

Weisseuberg.    u.    Malnitz.    Schicht.,   p.    134, 
fig.  121. 

V  —  —      Mantelli,  Fritscli.     Ibid.,  p.  134,  fig.  122. 

?  1888.       —  —  A.  Peroii.     L'Hist.  du  Terr,  de  Craie,  p.  151. 

Description. — Shell  of  small  convexity,  oval,  very  inequilateral,  higher  than  long. 

Antero-    and    postero-dorsal    margins   nearly  straight,   the   remainder  forming  a 

'  Also  recorded  from  the  Terebraiulina  zone  of  South  Dorset  by  Dr.  Barrois. 
-  This  may  bo  from  the  M.  cor-anguinnm  zone. 


LIMA.  23 


regular  curve.  Unibones  small,  cloric  together.  Apical  angle  usually  about  1(30°, 
but  sometimes  only  90°.  Ears  small,  the  posterior  larger  than  the  anterior. 
Anterior  area  of  moderate  size,  very  deep,  with  a  sharp  edge  and  numerous  radial 
ribs. 

Ornamentation  consists  of  numerous,  well-defined,  radial  grooves  with  distinct 
pits,  covering  the  entire  surface  of  the  shell.  The  grooves  are  straight  or  slightly 
wavy,  and  in  some  cases  are  linear,  in  others  broader,  the  latter  giving  the  appear- 
ance of  flattened  or  rounded  ribs  to  the  interspaces.  The  pits  in  the  grooves  some- 
times extend  into  the  sides  of  the  ribs.  New  grooves  may  be  introduced  near  the 
ventral  margin  or  occasionally  near  the  middle  of  the  valve.  In  well-preserved 
specimens  very  fine  concentric  ridges  are  sometimes  seen.  A  few  gi'owth-rings 
are  usually  present. 

Meatmrcmeids : 

(fi)  (V)  (8)  (9) 

17       K)       12       11  mm. 
lU       10       14      12    „ 

(1)  H.  2)lanus  zoue,  Cuxton.  (5 — 7)  A  quaih-atus  zone,  East  Haniliain. 

(2)  „  „       Cheveley.  (8)  M.  cor-anguinum  zone,  Willieriiii,'tou. 

(3)  ,,  ,,       Borsteil.  (9)  Uintacriiius  baud,  Devizes  Road,  Salisbury. 

(4)  A.  quad  rat  U!<  zone,  Wbadduu  railway  cuttiu*,',    I 


(1) 

(2) 

(3) 

(■i) 

(5) 

Length  , 

.  32 

32 

26 

21 

21 

Height  . 

37 

35 

30 

24 

22 

near  Salisbur 


V. 


Affinities. — This  species  is  distinguished  from  Linui  ILqicri  by  having  a  smaller 
apical  angle,  by  being  relatively  higher  and  shortei-,  with  the  valves  less  convex, 
the  anterior  area  relatively  smaller,  the  entire  surface  of  the  shell  always  orna- 
mented, and  the  grooves  usually  deeper. 

The  specimen  figured  by  d'Orbigny  as  Limd  Mnidelli  is  similar  in  foi'in  to  some 
examples  of  L.  cretacea,  but  d'Orbigny  states  that  the  furrows  are  shallow  and 
without  pits.  A  specimen,  however,  in  the  d'Orbigny  Collection  at  Paris  shows 
pits  in  the  grooves. 

Lima  Iseviusciila,  Sowerby  (in  Dixon)  is  probably  a  small  example  of  this 
species,  but  its  locality  and  horizon  are  not  stated. 

One  of  the  specimens  from  the  Plauer-kalk  of  Strehlen  figured  by  Geinitz 
(1872)  as  L.  Hoiwrl  (fig.  11)  agrees  very  closely  with  this  species. 

Dislrihution. — Zone  of  Terehratulina  of  Winchester.  Zone  of  Holuder  planus  of 
Twyford  and  Cheveley.  Zone  of  Micraster  cor-testudinariunt  of  Borstal  and 
Cuxton.  Zone  of  M.  cor-anguinum  of  Micheldever,  Witherington  and  Camp  Hill 
(South  Wiltshire).  Zone  of  Marsujjites  of  Highfield.  Uintacrinus  band  of  Devizes 
Road  (Salisl)my).  Zone  of  Arfiiiofnina.r  ipuHlyiitHs  of  Winchester,  East  Harnham, 
West  Harnham,  and  Milford  (8alisl>ury).  Zoue  of  Bclemnitella  mucronata  of 
Norwich.    Chalk  of  Trimingham. 


24  CRETACEOUS   LA:\1KLLIBRANCHIA. 


Tii.MA  (Ti.aoiostojMa)  MAiiUd'j'iANA,  (VOrhiipi //,  181-7 .     Plate  V,  figs.  (!((,//,  7r',?>. 

1847.     LiiMA  Masrotiana,  A.  d'Orhigny.     Pal.  Frauc.  Terr.  Cri't.,  vul.  iii.  p.  501. 

pi.  ccccxxiv,  figs.  1 — 4. 
1850.       —  —  irOrhifjny.     Prodr.  de  Pal.,  vol.  ii,  p.  247. 

1889.       —      (Kadtjla)  Marrotiana,  0.  Griepenlierl.      Seuou.  vou  Kouiyshiltor 

(Palseont.  Abhandl.,  vol.  iv),  p.  39. 

Non  1850.       -  -      Marottiana,  A.  Alth.    Geogn.-pal.  Beschreib.  v.  Lemberg  (Haidinger's 

Naturwiss.  Abliaudl.,  vol.  iii.  pt.  2),  p.  240, 
pi.  xii,  fig.  25.     (L.  AUhi,  Favre). 

Description. — Sliell  of  moderate  convexity,  oval,  more  or  less  trigonal.  Antero- 
dorsal  margin  rather  long,  nearly  straight ;  postero-dorsal  margin  much  shorter  ; 
the  remainder  forming  a  regular  curve.  Umbones  rather  small,  pointed.  Apical 
angle  about  105°.  Anterior  area  large,  deeply  depressed,  sharply  limited, 
ornamented  with  10  to  12  strong,  rather  narrow  ribs,  which  bear,  in  places,  small 
nodular  projections.  Ears  rather  large,  with  growth-ridges,  without  ribs ;  the 
posterior  rather  larger  than  the  anterior  ear. 

Ornamentation  consists  of  30  to  32  broad  ribs  with  a  few  smaller  ribs  near  the 
posterior  margin ;  the  ribs  are  smooth,  with  flattened  or  somewhat  rounded 
suniiuits,  and  are  separated  by  narrow  rounded  grooves.  The  grooves  show,  in 
places,  transverse  ridges  and  grooves  which  may  extend  to  the  sides  of  the  ribs, 
giving  them  a  notched  appearance.  Near  the  ventral  margin,  especially  in  old 
sjjccimens,  the  ribs  become  more  flattened  and  the  gi'ooves  shallower. 

Measurements : 

(1)  (2) 

Length       .  .  .  .     69         .         27  mm. 

Height       .  .  .  .     60         .         28     „ 

(1,  2)  Upper  Clialk  {B.  mucronata  zone),  Noi-wich.      The  measurements  of  the  larger  specimen  arc 
approximate  only. 

Affinities. — This  is  distinguished  from  other  species  found  in  the  Chalk  by  its 
strong  ribs.     In  Lima  Althi,  Favre,  the  ribs  are  more  numerous  and  not  so  broad. 

JAnia  Marrotiana  differs  from  most  of  the  species  which  are  referred  to 
Plarjiostoma  in  having  much  stronger  ribs,  but  in  other  respects  it  agrees  closely 
with  that  sub-genus. 

Remarks. — The  only  specimens  I  have  seen  are  from  Norwich,  where  it  appears 
to  be  rare.  The  shell  is  usually  more  or  less  crushed,  so  that  its  proper  outline  is 
distditi'd. 


LIMA.  25 

T i/2)es. —WOvhigny's  specimens  came  from  the  Lower  Senonian  of  Dordogne, 
Charente-Liferieure,  Cambrai,  and  Aube. 

Distrlhution. — Zone  of  Belemnitella  mucronata  of  Norwich. 


Suh-gcnus — Acesta,  II.  and  A.  Adants,  1858. 
('  Genera  of  Keceut  Mollusca,'  vol.  ii,  p.  558.) 
Lima  (Acesta)  longa,  Burner,  184L     Phite  V,  figs.  8(i,h,  9 — 11,  \2a,b. 

1836.     Lima  elongata,  F.  A.  Bonier.     Die  Versteiu.  d.  nurd-deutscli.  Oolith.-geb., 

p.  79,  pi.  xiii,  fig.  11  (nou  elongata, 
Sowerby). 

1841.        —       LONGA,  Romer.     Die  Versteiu.  d.  uord-deutsch.  Kreidegeb.,  p.  57. 

1847.       —  —A.  d'OrhUjny.     Pal.   Frau9.  Terr.   Cret.,  vol.  iii,  p.  529,   pi. 

ccccxiv,  figs.  13 — 16. 

1850.       —  —  —  Prodr.  de  Pal.,  vol.  ii,  p.  81. 

1865.       —  —      H.  Coquand.     Mou.  Aptien  de  I'Espagne,  p.  149. 

1868.  —  —      P.  de  Loriol.     Valaugieu  d'Arzier.  (Mater.  Pal.  Suisse,  ser.  4), 

p.  41,  pi.  iii,  fig.  11. 

1869.  —  —F.J.  Pictet  and  G.  Camjnche.     Foss.  Terr.  Crct.  Ste.  Croix 

(Mater.  Pal.  Suisse,  ser.  5),  p.  128, 
pi.  clxi,  figs.  6,  7. 
1871.       —  —       W.  A.  Ouster.     Protozoe  Helvetica,  vol.  ii,  pp.  104,  123.  ^ 

1877.       —  —      G.  Biihm.     Zeitsclir.  d.  deutsch.  geol.  Gesellscli.,  vol.  xxix, 

p.  235. 

1883.  —  —      W.  Keeping.     Foss.,  etc.,  Neoc.  Upware  and  Brickhill,  p.  112, 

pi.  v,  fig.  6. 

1884.  —      n.  sp.,  0.  Weerth.     Die  Fauna  des  Neocom.  iui  Teutoburg.    Waldo 

(Palajout.  Abliandl.,  vol.  ii),  p.  51. 
?  1895.       —      (Plagiostoma)  cf.  Eobinaldina,  F.  Vogel.     HoUiind.  Kreide,  p.  56. 
1896.       —      LONOA,   A.    Wollemann.     ZeitscLr.    der    deutscb.    geol.    GesellscL., 

vol.  xlviii,  p.  836. 
1900.       —  —  —  Die  Biv.  u.  Gastrop.  d.  deutscb.  u.  bolliiud. 

Neocoms  (Abhandl.  d.  k.  preussiscb.  geol. 
Land.,  N.  F.,  pt.  31),  p.  27. 

Description. — Shell  compressed,  sub-triangular,  rounded,  considerably  higher 
than  long,  of  small  obliquity.  Posterior  and  ventral  margins  convex;  anterior 
margin  straight.  Umbones  pointed,  close  together.  Apical  angle  small — about  70°. 
Posterior  ear  large,  not  separated  from  the  rest  of  the  valve  by  a  depression, 
ornamentoil    with    radial    ribs.      Anterior   ear   smaller,    nuich    higher   than    long. 

4 


(5) 

(6) 

21 

20  111111 

35 

32    „ 

2r>  ("RKTACKOUS    LA]\rKI.Ln?R.\X('ll  I.\. 

Anterior  area  lanceolate,  depressed,  limited  liy  a  sharp  edge,  ornamented  with 
radial  ribs. 

Ornamentation  consists  of  very  numerous,  small,  somewliat  flattened  ribs, 
separated  by  much  narrower  gi'ooves.  The  ribs  are  usually  wavy,  and  are  not  all 
of  equal  size ;  posteriorly  smaller  ribs  sometimes  alternate  with  larger.  The 
grooves  are  punctate  and  vary  sonieAvhat  in  width.  A  few  distinct  growth-lines 
are  seen,  below  which  the  direction  of  the  ribs  may  undergo  some  deflection. 

Measurements  : 

(1)  (2)  (3)  (4) 

Length  .         .37         35         31         23 

Height  .         .     G2         58         5G         37 

(1,  2,  3,  5)  Lower  Greensand,  Upware. 

(4)  Tcalby  Limestone,  North  Willinghain. 

(6)  Speetou  Clay,  Speetou. 

Ajfinities. — Lima  loiujn  has  a  smaller  apical  angle  and  is  relatively  shorter  than 
L.  undnta,  Deshayes ' ;  it  is  also  clearly  distinguished  by  the  absence  of  the  proiiiiiit'iit 
concentric  scales,  and  by  the  occurrence  of  pits  in  the  grooves. 

licmarks. — In  some  cases,  especially  when  the  specimens  are  not  perfectly 
preserved,  the  ribs  (as  remarked  by  Wollemann)  become  indistinct  on  the  middle 
of  the  shell.  This  is  the  case  in  specimens  from  the  Tealby  Limestone,  and  in  some 
from  the  Speeton  Clay,  in  which  the  iniddle  ])art  of  the  shell  is  almost  smooth. 
The  outline  of  the  shell  and  the  I'elative  size  of  the  posterior  ear  are  rather  variable. 

A  specimen  from  West  Dereham  (Plate  V,  fig.  13)  possesses  finer  ribs,  but  may 
perhaps  be  only  a  variety  of  this  species. 

Tjipes. — From  the  Ililsthon  of  EUigser  Brink.  A  specimen  from  the  same 
locality  (imperfect  on  the  posterior  side  of  the  umbo)  is  figured  by  d'Orliigny  and 
is  preserved  in  the  Museum  of  Palaeontology  at  Paris.  Two  oF  the  sj^'cimeiis  from 
Upware  figured  by  Keepuig  are  in  the  Sedgwick  Museum,  Cambridge,  and  auotiier 
is  in  the  collection  of  Mr.  J.  F.  Walker. 

JJistribulioii.—hovfev  Greensand  of  Upware,  Potton,  and  Priekhill.  Tealby 
Limestone  (zone  of  JJdemnites  brans oicensis)  of  North  Williughani.  Ujiper  part  of 
Speeton  Series  of  Speeton. 


TiiMA  (Acksta)  CLYPElFOKMis,  (VOrJihjii ij,  1817.     Text-figure  5. 

1847.     Lima  clypehokmis,  A.  d'Orhiijiitj.     Pal,  Fraiu;.  Terr.  Crt't.,  vol.  iii,  p.  543, 

pi.  ecccxvii,  figs.  9,  10. 
1860.       —  —  d'Orbigny.     Prodr.  de  Pal.,  vol.  ii,  p.  166. 

^  See  d'Orbiguy,  p.  528,  pi.  ccccxiv,  figs.  9 — 12  ;  Pictet  aiid  Campiche,  p.  133,  pi.  clxii,  fig.  1. 


LIMA. 


27 


I860.     Lima  cltpeiformis,  F.  J.  PU-ld  ami  G.  Campirhf.     Foss.  Terr.  Crt't.  Sto. 

Croix  (Mater.  Pal.  Suisse  scr.  5), 
p.  168. 
1871.     Radui.a   (Acesta)    cltpeiformis,    F.   Stolkzlca.      PaliBont.    Imlica,   Cret. 

Fauna    S.    India,    vol.    iii, 
p.  414. 


Description. — Shell  very  large,  compressed,  oval,  rounded,  only  slightly  oblique. 
Height  equal  to  or  slightly  greater  than  length.     Antero-dorsal  margin  more  or  less 


Fio.  5. — Lima  {Acesta)  elypeiformis,  d'Orbi^ny.     Upper  Greensnud,  Chard.     Eight  valve.     Taunton 

Museum,     x  |. 

straightened  and  relatively  short.     Ears  rather  small,  the  anterior  larger  than  the 
posterior.     Siu-face  of  shell  smooth,  except  for  growth-lamella)  at  intervals. 
Measurements  : 

Length 100  mm. 


Heiglit 


.     1()S     „ 


Upper  Greensand,  CLard. 


28  CRETACEOUS   LAMELLTRRANCHTA. 

Affimiies. — Lima  siihch/jmformis,  Fiitterer,^  is  stated  to  be  related  to  //.  rh/jm- 
formis. 

Rcmarls. — This  is  the  largest  species  of  JAina  known  in  the  Cretaceous  of 
England.  I  have  seen  two  specimens  only,  one  of  which  is  in  the  Museum  of  the 
Somersetshire  Archreological  and  Natural  History  Society  at  Taunton,  and  the 
other  in  the  Exeter  Museum.  The  occurrence  of  this  species  in  England  was  tirst 
recorded  by  Mr.  Jukes-Browne." 

Type. — D'Orbigny's  specimens  came  from  the  Ccnomanian  of  Le  Mans,  etc. 

DistrilmHoii. — Topmost  bed  of  the  Upper  Greensand  of  Chard. 


Suh-genus — Mantellum,  J.  F.  Bolfen,  1798. 
('Mus.  Bolten.;  2.  p.  100.) 
Lima  (Mantellum)  parallela  (Soiverhy)  1812.     Plate  V,  figs.  M-,  '[ba—ih 

1812.     MoDiOLA  PAEALLELA,  J.  ih  C.  Soiverhy.     Miu.  Condi.,  vol.   i,  p.  31,  pi.  ix 

(right-haud  top  figure). 
1842.     Lima  elegans,  A.  Leijmeric     Mi'm.   Soc.    gi'ol.  de  France,  vol.  v,  ]>.  27, 

pi.  vi,  fig.  6.    {Non  Dujardiu,  non  Nilsson. ) 

1845.  —      elonoata,  E.  Forbes.     Quart.  Jouru.  Geol.  Soc,  vol.  i,  p.  248. 

1846.  —      ELEGANS,  A.  Leymerie.     Statist,  geol.  et  min.  de  rAubc,  pi.  vi,  fig.  7. 

1847.  —      CoTTALDiNA,  A.  (TOrhigmj.     Pal.  Fran9.  Terr.  Crct.,  vol.  iii,  p.  .''>37, 

pi.  ccccxvi,  figs.  1 — 5. 
18,50.       —  —  d'Orhigny.     Prodr.  de  Pal,  vol.  ii,  p.  119. 

1854.  —      PARALLELA,  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  171. 

1855.  —      CoTTALDiNA,  G.  Gotteau.     Moll.  Foss.  de  I'Yonne,  p.  101. 

1858.       —  —  J.  Vilanova-y-Piera.      Mem.  geog.-agric.  de  Castellon, 

pi.  ii,  fig.  15. 
—  —      PAEALLELA,  F.  J.  Pictet  and  E.  Benevier.    Foss.  Terr.  Aptiou  (Mator. 

Pal.  Suisse,  ser.l),  p.  126, 
pi.  xix,  fig.  1. 
18C5.      —  —         H.  Coquand.     Men.  Aptien  de  I'Espagne,  p.  148. 

1869.       —      COTTALDINA,  F.  J.  Pictct  uiul  G.  Campicke.     Foss.  Terr.  Cret.  St«. 

Croix  (Mater.  Pal.  Suisse,  ser.  5), 
p.  151,  pi.  elxvi,  fig.  1. 

1883.  —      rARRiNQDONENSis,  W.  Keejuug.     Foss.,  etc.,  Neoc.  Upware  and  Brick- 

hill,  p.  112,  pi.  V,  fig.  12. 

1884.  —     COTTALDINA,   O.  WpcrtJi.     Die   Fauna   des  Neocom.   im  Teutoburg. 

Walde  (Palaeont.  Abhandl.,  vol.  ii),  p.  52. 

'  '  Kreidebild.  d.  Santa  Croce  in  den  Venctianer   Alpen '   (Pala;ont.   Abhandl.,  vol.  vi,  1892), 
p.  78,  fig.  23. 

2  '  Proc.  Somerset  ArchEool.  and  Nat.  Hist.  Soc.,'  vol.  xlix,  1903. 


LIMA.  2y 

1895.     Lima  Cottaldina,   G.  Maas.     Zeitschr.  <ler  deutscli.  gcol.  Gesellsch.,  vo  . 

xlvii,  p.  267. 
—  —      (Rabttla)  Cottaldina,  F.  Vognl.     HollaiKliscli.  Kreide.,  p.  56. 

1900.       —      Cottaldina,  A.    WoJIrmnnn.     Die   Biv.   u.  (iastrop.   d.   deutsch.   n. 

liolliind.  Neocoms  (Abliandl.  d.  k. 
preussisch.  geol.  Land.,  N.  F.,  pt. 
31),  p.  35,  pi.  ii,  figs.  2,  3. 

Non  1847.       —      parallela,  (VOrhupiy.     (See  p.  31). 

Description. — Shell  modei'ately  convex,  oblique,  oval  or  rounded-ojjlong,  higher 
than  long.  Antero-dorsal  margin  long,  nearly  straight,  more  or  less  parallel  with  the 
postero- ventral  margin ;  postero-dorsal  margin  short,  more  or  less  nearly  straight. 
Anterior  margin  regularly  rounded.  Umbones  sharp,  only  slightly  curved  ;  apical 
angle  about  90°.  Ears  of  moderate  size.  Anterior  area  rather  large,  slightly 
convex  ventrally,  depressed  near  the  umbo,  usually  smooth  except  for  growth- 
lines. 

Ornamentation  consists  of  18  to  20  principal  ribs,  and  sometimes  of  a  few- 
smaller  ribs  near  the  posterior  margin.  The  principal  ribs  are  roof-like  with  sharp 
summits ;  they  are  strongest  on  the  antero-dorsal  part  of  the  valve  and  ])econie 
less  elevated  and  rather  more  widely  separated  in  passing  posteriorly  ;  the  two  or 
three  anterior  ribs  (near  the  anterior  area)  are  rather  smaller  and  closer  together. 
A  small  rib  occurs  at  the  bottom  of  the  furrows  between  the  main  ribs ;  smaller 
linear  rilis  may  occur  on  the  sides  of  the  principal  ribs,  especially  on  the  posterior 
part  of  the  shell.     Fine  concentric  growth-lines  are  seen  on  the  ribs  and  furrows. 

Measurements  : 

(1)  (2)  (3)  (4)  (.-i) 

Length       .       2G       26       25       23       23 
Height       .       21       22       20       19       18 

(1,  4)  Perna-hcd,  Atherfield. 
(2,  5)  Hythe  Beds,  Lympue. 

(3)  Lower  Greensand,  Upware. 
{G,  7)  Hythe  Beds,  Hythe. 

(8)  Ferruginous  Sands,  Shanklin. 

Affinities. — This  species  is  closely  allied  to  L.  Enijennna,  d'Orbigny,"  but  in 
the  latter  the  ribs  do  not  decrease  in  size  nor  become  more  widely  separated  on 
the  posterior  part  of  the  shell,  and  the  suuill  rib  in  the  furrows  is  absent  or 
indistinct. 

L.  parallela.  is  distinguished  from  L.  gaultina  (p.  31)  l)y  l)eing  relatively 
shorter  and  less  compressed,  by  the  ribs  on  the  posterior  part  of  the  shell  being 

'  'Pal.  Fran9.  Terr.  Cn't.,'  vol.  iii  (1847),  p.  527,  pi.  ccccxiv,  figs.  5 — 8;  Pictet  and  Campiche, 
'Terr.  Cret.  Ste.  Croix  '  (1869),  p.  142,  pi.  clxiv.  figs.  4,  5. 


(6) 

(-) 

(S) 

22 

19 

14  mm 

17 

k; 

11     „ 

30  CRETACEOUS   LAMELTJBEANCHIA. 

more  distinctly  siiialk'r  tluiii  those   on   tlio   anterior  pnrt,  nnd    l)y  tlie   presence  of 
tlie  small  rib  at  the  l)ottom  of  each  groove.     Sec  also  L.  J'lii-i-iiiiiilniiri/sis  (below). 

L.  exjmnsa,  Foi-bes,'  fi-oni  the  ITythc  Beds  of  Hythc,  is  known  to  me  only  from 
the  type  specimen  which  is  preserved  in  the  Musenm  of  the  Geological  Society 
(No.  2050).  It  is  an  internal  cast  in  clay,  somewhat  crnshed,  and  shows  the 
ribbing  only  imperfectly.  I  think  it  is  i)robal)ly  an  example  of  L.  paralJcht,  bnt 
more  specimens  from  the  same  horizon  are  needed  Ijefore  a  confident  opinion  can 
be  given.  Similar  remarks  apply  to  L.  lingua,  Forbes,"  which  comes  from  the  same 
horizon  and  locality,  and  is  likewise  preserved  in  the  Museum  of  the  Greological 
Society  (No.  2058). 

This  and  the  following  eight  species  are  provisionally  referred  to  the  sub-genus 
Md  11 1  I'll  urn,  with  which  they  agree  in  the  form  of  the  shell  and,  in  many  cases,  in 
the  general  character  of  the  ornamentation.  They  differ,  however,  from  the  type 
of  Maidelliim  in  having  the  valves  closed  or  almost  closed,  but  there  is,  as  Phillipi 
has  pointed  out,  every  transition  from  the  species  in  wliicli  tlio  \;ilves  gape  \vi<lcly 
to  others  in  which  they  are  closed. 

I'riinirJrx. — This  species  shows  a  fair  amount  of  variation  in  the  ]iro]iortions  of 
length  and  height,  and  also  in  the  obliquity  of  the  shell. 

The  type-specimen  of  L.  2^'i>'M''l'^  is  an  internal  cast,  and  consequently  all 
writei's  liave  found  it  practically  impossible  to  make  out  the  charact(>i's  of  the 
species  from  Sowerby's  figure.  A  comparison  of  the  type  with  better  preserved 
specimens  leaves  no  doubt  in  my  mind  that  Sowerl)y's  species  is  really  identical 
with  the  form  described  by  d'Orbigny  as  L.  ('(itlnJiVuni.  The  latter  author 
I'cfei'red  a  species  found  in  the  Gault  (/y.  ijditHiiKi,  p.   ol)  to  L.  pandlcla,  Sowerby. 

'I'l/ji'-x. — The  type  is  from  the  Ilythe  Beds  of  Maidstone  and  is  preserved  in  the 
Hi'itish  Museum  (No.  4o,2i)2).  The  specimen  from  Upware  figured  as  L.  faniiiij- 
(Idiit'iisis  by  Keeping  is  in  the  Sedgwick  Museum,  Cambridge. 

Dixfrihiitiou. — Prrna-hed  and  Atherfield  Clay  of  Atherfield.  Ferruginous  Sands 
of  Shanklin.  Hythc  licds  of  Hythc,  T.ympne,  and  Maidstone.  Sandgate  Beds  of 
Sevenoaks.  Folkestone  Beds  of  Folkestone,  [jower  Greensand  of  Faringdon  and 
Upware.     Speeton  Clay  of  Speeton. 


Lima  (Mantktjjim)  farringdonensis,  Sharpr,  1853. 

1853.     Lima  farringdonensis,  D.  Sharpe.     Quart.  Jdiini.  Gcol.  Soc,  vol.  \,  p.  198, 

pi.  vi,  fig.  2. 

Non  1883.       —  «     —  W.  Keeping.     Fuss.,  etc.,  Neoe.  TJpware  and  ■Brick- 

hill,  p.  112,  pi.  V,  tig.  12. 

'  'Quart.  JouiTi.  Geol.  Soe.,'  vol.  i  (1845),  p.  249,  pi.  iii,  fig.  11. 
-  Ibi.L,  p.  249,  pi.  iii,  fig.  10. 


LIMA.  31 

Renin fliS. — The  cliiof  cliavucter  in  which  Liittit  Juningtloiiru.sis  differs  from 
L.  parallela  seems  to  be  in  the  possession  of  well-marked  ribs  over  the  whole  of 
the  anterior  area.  It  also  differs  from  the  majority  of  examples  of  L.  parallda  in 
that  the  ribs  only  decrease  in  size  to  a  very  small  extent  in  passing  from  the 
anterior  to  the  posterior  part  of  the  shell;  and  further,  the  shell  is  less  inequilateral 
than  is  usual  in  L.  parallela. 

I  am  inclined  to  regard  Lima  farrliigdonensis  as  not  more  than  a  variety  of 
L.  paraUcla,  but  without  better  material  it  is  impossible  to  express  a  confident 
opinion.  Almost  all  the  specimens  seen  are  in  the  condition  of  intei-nal  casts  in  a 
brownish  ferruginous  sandstone. 

Type. — The  figure  given  by  Sharpe  is  taken  from  a  gutta-percha  cast  of  an 
external  mould.  It  was  obtained  from  Seende  and  is  preserved  in  the  Museum  of 
the  Geological  Society. 

Bidribution. — Lower  Grcensand  of  Seende  and  Faringdon. 


Lima  (M.vntelt.um)  uaultina,  nom.  nov.     Plate  V,  figs.  IG — 2(>. 

?  1827.     Plagiobtoma  elongata,  /.  Jc  C  Smvcrhij.     Miu.  Couch.,  vol.  vi,  ji.   113, 

1)1.  dlix,  fig.  2  (upper  figure  ouly). 
1847.     Lima  paeallela,  A.  d'Orhitjuy.     Pal.  Frauc.  Terr.  Crt't.,  vol.  iii.  p.  539, 

pi.  ccccxvi,  figs.  11 — 14. 
1850.       —  —  d'Orhlijiiij.     Prodi-,  de  Pal,  vol.  ii,  p.  138. 

1855.       —  —  G.  ColteiiH.     Moll.  Foss.  de  ITouue,  p.  101. 

1854.       —      elongata,  /.  Murris.     Cat.  Brit.  Foss.,  ed.  2,  p.  171  (jjaiiim). 
1875.       —  —  A.  J.  Jukes-Browne.     Quart.  Jouru.  Geol.  Soc.,  vol.  xxxi, 

p.  2;i(i. 
1897.       —      parallela,  R.  B.  Ncwtun.     Proc.  Dorset  Nat.  Hist,  aud  Autiij.  Field 

Club,  vol.  xvii,  p.  88,  pi.  iii,  fig.  11. 
IPOO.       —  —  E.    T.   Newton  aud  .1.  J.  Jukes-Browne.     Cret.  Eocks  of 

Britain,  vol.  i,  p.  449. 

Nou  1850.     Plagiostuma   parallelus.  J.  de  C.  Suwerbij  iu  F.  Duoii.     Geol.  Sussex, 

p.  35t)  (p.  386,  ed.  2),  pi.  xxviii, 
fig.  16  (=1/.  elongata,  Sowerby). 

Description. — Shell  rather  compressed,  sulj-cpiadrangidar  or  nearly  oblong,  very 
oblique,  nuich  longer  than  high,  rounded  posteriorly  ;  antero-dorsal  margin  long 
and  nearly  straight,  almost  parallel  with  the  postero-ventral  margin.  Apical  angle 
about  100°.  Umbones  pointed,  close  together.  Ears  of  moderate  size,  the  anterior 
larger  than  the  posterior.  Anterior  area  lai-ge,  slightly  concave  dorsally,  orna- 
mented with  fine  radial  ribs. 

Ornamentation  consists  of  18  to  '20  main  rilis  witli  a  few  smaller  ribs  pos- 
teriorly.      The    ribs    are     strong,    witli    sharp    summits,    but    become    somewhat 


32  CRETACEOUS   LAMET/IJBRANCHIA. 

weaker  posteriorly.    The  sides  of  the  ribs  are  oriianiented  witli  fine  radial  ribs,  and 
at   the   summit  there  is  sometimes  a  rib  with  pointed  projections.      Concentric 
growth-lines  are  present. 
Measurements  : 

Length 
Height '     . 


(1)               (2)               (3)              (4) 

(5) 

(6) 

39         3-1         29         29 

28 

17  mm 

28         23         20         18 

20 

I'' 

(1,  4)  Gault,  Black  Veu. 

(2,  3,  5,  6)  Gault,  Folkestone. 

Affinities. — Lima  Itcviana,  Pictet  and  Roux,-  appears  to  differ  from  this  species 
in  having  a  small  rib  at  the  bottom  of  the  groove,  and  in  being  relatively  shorter. 
Pictet  and  Canii)iche  state  that  the  small  rib  is  not  always  present.  I  have  seen 
no  trace  of  such  a  rib  in  even  the  best  preserved  examples  of  L.  gunltina.  See  also 
Lima  elomjata  (p.  36). 

Bemarls. — One  of  the  specimens  figured  by  Sowerby  as  Flagiostoma  cloinjutu 
(the  upper  figure  2  of  Plate  DLIX)  is  probably  an  exanii)le  of  this  species,  but  since 
it  is  an  internal  cast  only,  it  is  difficult  to  be  sure  of  its  identity  without  seeing 
other  specimens  from  the  same  horizon.  The  specimen  in  question,  however, 
asfrees  in  form  and  in  the  characters  of  the  ribs  with  other  internal  casts  which 
imdoubtedly  belong  to  this  species.  D'Orbigny  referred  this  species  to  Lima 
■paraUcla  (Sowerby)  and  also  included  with  it  L.  cloiujata,  Sowerby  (p.  3-1). 

Types. — The  specimen  figured  by  Sowerby,  mentioned  above,  is  stated  to  come 
from  the  "  Greensand  of  Folkestone."  D'Orbigny's  specimens  of  LAma  paralhla, 
d'Orbigny  non  Sowerby,  came  from  the  Gault  of  Gerodot  and  Dienville  (Aube). 

Distribution. — Gault  of  Folkestone  (zones  ii,  vii,  ix).  Gault  of  Veutnor  and 
JJlack  Ven.  Cambridge  Greensand  (derived).  Upper  Greensand  (zone  of 
ScldcJOidHichia  roslrata)  of  Devizes.  Internal  casts  from  the  Speeton  Clay  (zone  of 
Belemnitcs  jacidum,  C  11)  seem  to  be  indistinguishable  from  this  species. 


Lima  (]V1anteija:m)  inteulinkata,  Jukes- Bruwtw,  1877.     Plate  VI,  figs,  ia,  I/. 

1877.     Lima    interlinbata,   A.    J.    Jukes-Browne.      Quart.    Journ.    Geol.    Soc, 

vol.  xxxiii,  p.  502,  pi.  xxi,  fig.  10. 

Dfxrrqilii)n. — Shell    moderately  convex,    roundetl-ublong.     Umbones    and   ears 
uuL  seen. 

'  Measured  perpeinlicular  to  the  liiugc-line. 

2  'Moll.  Foss.  Grts  verts  ile  Geuive  "  (1852),  p.  484,  pi.  xl,  fig.  5  ;   F.  J.  Pietet  aud  G.  Caiupiehe, 
'Foss.  Terr.  Crct.  Sto.  Croix  '  (Mater.  Pal.  Suisse,  ser.  5,  1869),  p.  156,  pi.  clxvi,  figs.  4,  5. 


LIMA.  33 

Ornamentation  consists  of  10  to  12  sti'ong  ribs  witli  l)road  interspaces.  On  the 
posterior  part  of  the  shell  the  ribs  are  more  widely  separated  and  the  interspaces 
flatter  than  on  the  anterior  part.  In  the  interspaces  there  are  small  i^adial  ribs 
separated  by  broad  spaces. 

Bemarlcs. — The  only  specimens  seen  are  a  few  imperfect  internal  moulds  with 
very  small  portions  of  the  shell  preserved.  L.  iiderlincata  a^ipears  to  l)e  allied  to 
L.  gaultlua  (see  above)  but  is  distinguished  by  possessing  fewer  ribs  with  broader 
and  flatter  interspaces.  The  smaller  radial  ribs  are  perhaps  also  better  developed 
than  in  L.  gaultlua. 

Tijpe. — In  the  Sedgwick  Museum,  Cambridge. 

Didrihuiion. — Cambridge  Greensand  (derived  from  the  Gaidt). 


Lima  (Maxtelluji)  iNXEUMEiUA,  iVOrJihjinj,  1847.     Plate  VI,  figs.  2 «,  ?^,  3,  4a — c. 

1847.     Lima  inteemeuia,  A.  d'Oi-hijnij.     Pal.  Fiau9.  Terr.  Cret.,  vol.  iii,  p.  550, 

pi.  ccccxxi,  figs.  1 — 5. 
1850.       —  —  d'OMijiiij.     Prodr.  de  Pal.,  vol.  ii,  p.  167. 

1869.       —  —  F.  J.  Pldd  and  G.   Campkhc.     Foss.  Terr.  Cret.  Ste. 

Croix  (Matur.  Pal.  Suisse,  ser.  5), 
p.  168. 
?  1877.       —  —  A.  Fritsch.     Stud,  im  Gebietc  derbiilim.  Kreideformat. : 

II,   Weisseuberg.   u.    Maluitz.    Scluclit., 
p.  134,  fig.  123. 

Descriptlou. — Shell  moderately  compressed,  oblique,  oval  or  rounded-ol:)long, 
higher  than  long.  Antero-dorsal  border  rather  long  and  roughly  parallel  to  tlie 
slightly  curving  postero-ventral  border;  both  curve  gradually  and  regularly  to 
join  the  posterior  border.  Postero-dorsal  shorter  than  the  antero-dorsal  border. 
Umbones  inconspicuous,  close  together.  Apical  angle  about  100°.  Ears  small,  of 
nearly  equal  size,  the  posterior  with  three  or  four  small  radial  ribs  and  with  growth- 
ridges.  Anterior  area  moderately  large,  slightly  convex  except  near  the  umbones, 
smooth  or  with  a  few  small  ribs  at  the  sides. 

Ornamentation  consists  of  20  to  23  ribs.     Those  on  llie  antero-ventral  region 

are    strong  and  roof-like,  and,  in    old    specimens,    bear    a    smaller   rilj    on    each 

side;  posterior  to  this  region  the  ribs  become  much  smaller  and  less  elevated, 

some  being   almost  linear   and   Avith  broad  and  nearly  flat  interspaces.     At  the 

bottom  of  the  furrows  and  in  the  middle  of  the  flat  interspaces  there  is  a  linear 

rib.      In    well-preserved    specimens    very    fine    radial    ribs    and    concentric    lines 

are  seen. 

5 


34  CRETACEOUS   LAMELLIBRANCHIA. 


Measurements : 

(1) 

(a) 

(3) 

Length 

35 

30 

30  nun. 

Height 

31 

28 

2G    „ 

Thickness 

18 

17 

16    „ 

(1,2)  Kye  Hill  Sands,  Warminsler. 

(3)  Upper  Greensand,  Longbridge,  Devizes. 

Affinities. — This  species  is  closely  allied  to  Liina  parallela,  Init  is  distinguished 
by  being  less  convex  (especially  in  the  region  of  the  umbones),  Ijy  Ijoing  rather 
shorter  and  higher,  and  by  the  ribs  decreasing  in  size  rather  more  rapidly  when 
traced  from  the  antero-ventral  region  to  the  posterior  region.  The  fine  radial  orna- 
mentation is  also  perhaps  rather  better  marked  than  in  L.  parallela. 

L.  intermedia  differs  from  L.  elongata  (see  below)  in  being  less  convex,  relatively 
shorter,  in  the  ribs  being  less  elevated  and  decreasing  in  size  posteriorly,  and  in  the 
absence  or  indistinct  character  of  the  ribs  on  the  anterior  area. 

It  is  also  relatively  shorter  and  higher  than  Lima  gaultina,  and  the  ribs  on  the 
posterior  half  are  much  smaller  and  have  broader  and  flatter  interspaces.  The 
intermediate  rib  is  distinct  in  L.  intermedia,  but  is  absent  or  indistinct  in  L.  ydtdtina. 

Type. — From  the  Cenomanian  of  Le  Mans. 

Distrihiitlon. — Upper  Greensand  (zone  of  Pecteii  asper)  of  Longbridge,  near 
Devizes.     Rye  Hill  Sands  of  Warminster. 


Lima  (Mantellum)  elongata  (Sowerbij),  1827.     Plate  VI,  figs.  5,  6a— c,  7a,  b. 

1822.     Plagiostoma,  G.  Mantell.     Foss.  S.  Downs,  p.  129,  pi.  xix,  fig.  1. 
1827.  —  ELONGATA,  /.  (le  C.  Sowcrhij.     Min.  Couch.,  vol.  vi,  p.  113, 

pi.  dlix,  fig.  2  (lower  tigiu-e). 
?  1847.     Lima  Astieeiana,  A.  d'Orbiijny.     Pal.  Frdiu;.  Terr.  Cret.,  vol.  iii,  p.  549, 

pi.  ccccxx,  figs.  4 — 7. 
1850.     Plagiostoma  paeallelus,  /.  de  C.  Sowcrhy  in  F.  Dixon.      Geol.  Sussex, 

p.  350  (p.  386,  ed.  2),  pi.  xxviii,  fig.  16. 
1854.     Lima  elongata,  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  171  (jMrtim). 

1869.  —  —  F.  J.  Fidct  and  G.  Cttm]jiche.     Foss.  Terr.  Cret.  Ste.  Croix 

(Mater.  Pal.  Suisse,  ser.  5),  p.  168. 

1870.  —  —  F.  R'dmer.     Geol.  vou  Oberscliles.,  p.  343,  pi.  xxix,  fig.  1. 
?  1876.       —           —  H.  Deicke.     Toui-tia  vou  Miillieim  a.  d.  liuhr,  p.  27. 

'^  1877.       —  —  G.  Bijhm.     Zeitsclir.  d.  deutsch.  geol.  Gesellscli.,  vol.  xxix 

p.  234. 
1897.       —  —  R.  Leonhard.     Kreideformat.   iu   Oberscliles.  (Palajonto- 

grapliica,  vol.  xliv),  p.  47. 
1904.       —  —  E.   T.   Newton  and  A.  J.  Jukes-Browne.     Cret.  Kocks  of 

Britain,  vol.  iii,  p.  451. 


LIMA.  35 

Noil  188G.     Lima  elonoata,  A.  Gohlfiufs.     Petref.  Germ.,  vol.  ii,  p.  87,  pi.  cii,  fi;,'.  13 

{L.  Miinsteriana,  (l'Orl)igny). 
—  —  —  F.  A.  lli'imcr.     Vcr.stoiii.  nord-deutscli.  Oolith.-geb.,  p.  70, 

111.  xiii,  fig.  11  {L.  lontjn,  Komor,  1841). 
?  —    1841.       —  —  F.  A.  Biimer.     Die  Verstein.  d.  iiord-dcutscli.  Kreidegeb., 

p.  5G. 

—  1845.       —  —  H.  Forhes.     Quart.  Joum.   Geol.  Soc,  vol.   i,  p.  248  (L. 

parallela,  Sowerby). 
? —    1846.       —  —  A.E.Reuss.     Die  Verstein.  der  bijlim.  Kreideformat.,  pt.  2, 

p.  33,  pi.  xxxviii,  fig.  6,  non  9  (=  i.  Reiigm, 
d'Orb.). 

—  1863.       —  —  A.  V.  Stromhech.     Zeiisclir.  d.  deutsch.   geol.   Gesellsch., 

vol.    XV,    p.    104    {L.    Schmeisseri, 
Wollemauu). 
?  —    1872.       —  —  H.  B.   Geinitz.      Das  Elbtlialgeb.  in  Sachscn  (Palffiouto- 

graphica,  vol.   xx,  pt.  2),  p.  40,  pi.  ix, 
figs.  9,  10. 
'■  —    1877.       —  —  A.  Fritscli.     Stud,  im  Gebiete  der  bolim.  Kreideformat.: 

II,  Weisseuberg.  u.  Malnitz.  Scbicht.,  p.  132, 
fig.  116. 

Description. — Shell  of  moderate  convexity,  subquadrangular  or  nearly  olilonp-, 
rounded  anteriorly,  mucli  longer  than  high.  Antero-dorsal  margin  long,  nearly 
straight,  and  nearly  parallel  with  the  postero-ventral  margin;  postero-dorsal 
margin  short,  nearly  straight.  Apical  angle  about  100°.  Umbones  sharp,  close 
together.  Ears  of  moderate  size.  Anterior  area  large,  the  dorsal  part  slightly 
concave,  ornamented  with  from  five  to  seven  fairly  strong  riljs  which  are  crossed 
by  fine  growth-ridges. 

Ornamentation  consists  of  19  or  20  very  strong  ribs,  with  sharp,  and  some- 
times (especially  on  the  dorsal  part  of  the  shell)  slightly  serrate  summits.  The 
ribs  have  usually  at  their  summits  a  distinct  ridge  with  a  shallow  fiu-row  on  each 
side,  which  sometimes  gives  rise  to  the  appearance  of  a  ridge  on  each  side  of  the 
rib.  The  grooves  between  the  main  ribs  are  deep,  rounded,  distinctly  limited,  and 
of  a])out  the  same  width  as  the  ribs.  On  the~dorsal  portions  of  the  shell  fine  radial 
ribs  occur  on  both  ribs  and  grooves ;  on  the  ventral  portions  they  are  not  seen. 
Fine  concentric  growth-lines  cross  both  ribs  and  grooves,  and  some  few  (at 
intervals)  are  more  distinct. 

Measurements : 

Length 
Height 

(1.  3,  5,  6)  Chalk  Marl,  Folkestone. 

(2)  H.  suhyhthomg  zone,  Stoke  Ferry. 
(4)  Chalk  Marl,  Veutnor. 


(1) 

(2) 

(3) 

(4) 

(5) 

(6) 

34 

27 

26 

25 

24 

24  mm 

24 

18 

20 

20 

18 

17  „ 

36  CRETACEOUS    LAMELLIBRANCHIA. 

Affinities^. — This  species  agrees  in  form  witli  Lima  gauUiva  (p.  31),  but  is 
distinguished  (1)  by  the  stronger  ribs  on  tlic  anterior  area,  (2)  by  the  grooves  being 
relatively  broader  and  more  distinctly  limited,  (3)  l)y  the  ribs  being  more  elevated, 
(4)  by  the  fine  radial  ribs  being  usually  indistinct  except  on  the  dorsal  portions  of 
the  shell. 

The  form  from  the  Pliiner-kalk  (Turonian)  of  Saxonj'  figured  as  JAma 
elongata  by  Geinitz  seems  to  differ  from  this  species  in  having  fewer  and  more 
rounded  ribs,  and  in  the  ribs  being  more  Avidely  separated  on  the  posterior  part  of 
the  shell  than  elsewhere.  Similar  remarks  apply  to  the  specimen  figured  by 
Fritsch.  Without  the  opportunity  of  comparing  specimens  I  am  unable  to  give  a 
definite  opinion  as  to  the  Turonian  form  being  distinct  from  L.  chmfintd. 

Lima  AMerianii,  d'Orbigny,  is  perhaps  identical  with  Z.  elongata,  but  the  summits 
of  the  ribs  appear  to  be  somewhat  more  rounded. 

Lima  Beussi,  d'Orbigny  {L.  ehngata  of  Reuss)  seems  to  differ  from  Lj.  elongata 
in  having  a  smaller  apical  angle. 

BemarJcs. — Under  the  name  FJagiostoma  ehngata  Sowerby  figured  two  species. 
It  seems  advisable  to  retain  the  name  elongata  for  the  one  shown  in  the  lower  of  his 
two  figures,  since  that  form  had  liecn  previously  figured  and  described  (but  without 
a  specific  name)  by  Mantell,  and  Sowerby  refers  to  Mantcll's  figure  as  an  example 
of  Plagiostoma  elongata. 

T)jpe>i. — I  have  not  seen  the  specimen  figured  by  Mantell.  Sowerby's  type, 
from  the  Chalk  Marl  of  Hamsey,  and  also  the  specimen  figured  in  Dixon's  work  are 
in  the  British  Museum. 

Distribution. — The  range  is  from  the  Chloritic  Marl  to  the  zone  of  TTolaster  snli- 
glohof^ns.  Chloritic  IVIarl  of  Eastbourne  and  the  Isle  of  Wight.  Chalk  Marl  of 
Ventnor,  Folkestone,  and  Prince's  Risborough.  Totternhoe  Stone  of  Arlesey. 
Zone  of  IIola><t('r  siihijliit)(i><n><  of  l^luo  Bell  Hill  (Bnrhani),  Stoke  Ferry,  and 
Hunstanton. 


Lima  (Maxtelta-m)  klonciata,  var.  echinata,  Ethf ridge,  1881.  Plate  VI,  figs.  8,  9  a — c. 

1881.     Lima  eohinata,  R.  Etheridgr.     lu  Penniiuj  and  Jukes-Browne,  Geol.  Cam- 
bridge, p.  144,  pi.  ii,  fig.  2. 

Remarks. — The  examples  described  by  Etheridge  as  Lima  echinata  agree 
perfectly  in  form,  in  size,  and  in  the  number  and  character  of  the  ribs  with  Tj. 
elongata,  but  on  the  ridge  at  the  summit  of  each  rib  there  is  a  roAV  of  short  spines 
which  are  frequently  rounded  and  stumpy,  and  on  each  side  of  the  rib  (outside  the 


LIMA.  37 

slmlloAV  groove  nuMitioiied  in  tlic  description  of  Tj.  plonfjafd)  tliore  is  another  row  of 
similar,  but  slightly  smaller  spines.  In  the  furrows  between  the  main  ribs  there 
are  transverse  ridges. 

On  account  of  the  close  resemblance  in  the  form  and  ribbing  of  //.  orhinaid 
to  L.  olongntn,  and  also  from  the  fact  that  \n  some  specimens  of  the  former  the 
ornamentation  of  the  ribs  is  absent  from  a  part  of  the  shell  and  the  ribs  are  tlion 
indistinguishable  from  those  of  L.  cloiigatu,  I  am  led  to  consider  L.  rchinata  as  not 
more  than  a  variety  of  L.  elongafa.  Further,  in  some  specimens  of  L.  doiigata  the 
summits  of  the  ribs  are  serrate. 

L.rlonr/nta  var.  echinata  pi^esents  some  resemblance  to L.Schmeiswri,  Wollemann,' 
from  the  BJiotomagensis-'Pliinev  of  Liineburg. 

Ti/pes. — In  the  Sedgwick  Museum,  from  Burwell. 

Diiifrihiifinu. — Totternhoe  Stone  {Tfdhi.^fi'v  siihglohnftus  zone)  of  Burwell  and 
Cherry  Hinton.  Also  recorded  in  the  '  Geological  Survey  Memoirs  '  from  the  zone 
of  Schhriiliiichia  cariaiis. 


Lima  (Mantellum)  rAXTATiRKUEXSis,  nom.  nov.     Plate  VI,  figs.  10a,  h,  11,  12. 

1881.  Lima  ornata.  7?.  Ether'nhje.  In  Pcnnimj  and  Jukes-Browne,  Geol.  Cam- 
bridge, p.  144,  pi.  iii,  fig.  2  (lion 
ornata,  d'Orbigny,  1847 ;  nr>ii 
ornata,  Buvignicr,  1852). 

Dpscriptinn. — Shell  moderately  convex,  oval  or  rounded-oblong.  Anterior 
margin  rounded.     Uml)ones  and  ears  not  seen. 

Ornamentation  consists  of  16  or  17  main  ribs  with  a  few  small  ribs  at  the 
posterior  end.  The  anterior  ril)s  are  sti'ong,  roof-like,  with  ridged  summits ; 
posteriorly  the  ribs  become  less  prominent  and  the  interspaces  less  depressed. 
Both  ribs  and  grooves  are  ornamented  with  fine,  well-developed  ribs,  which  arc 
closer  together  on  the  ribs  than  in  the  grooves ;  usually  three  or  four  occur  on 
each  side  of  a  main  rib  and  three  in  each  erroove.  iSTumerous  concentric  rids:es 
occur  and  give  rise  to  spiny  projections  where  they  cross  the  fine  radial  ribs. 

Affinitipn. — In  form  this  appears  to  be  similar  to  L.  pamllehi  (p.  28),  but  has 
fewer  ribs  and  is  much  more  highly  ornamented.  The  small  rib  at  the  bottom  of 
the  groove  is  not  distinguishable  from  the  other  ribs. 

It  is  more  convex,  has  fewer  ribs,  and  has  the  fine  ornamentation  better  developed 
than  in  L.  intermedia. 

Iii-Diarh. — This  species  is  known  b}'  three  specimens  only.  All  arc  imperfect 
near  the  umbo,  but  the  fine  ornamentation  is  well-preserved. 

'  Abhandl.  d.  k.  proussiscli.  geol.  Landesanst.,  N.  F.,'  Heft  37  (1902),  p.  5.1,  pi.  vii,  fig.  9. 


38  CRETACEOUS   LAMELLIBRANCHIA. 

Oil  account  of  the  name  ornata  having  been  previously  used  by  d'Orbigny  and 
by  Buvignicr  for  other  species  it  is  necessary  to  substitute  some  other  name. 

Ti/pf's. — From  the  Cambridge  Greensand  (indigenous),  preserved  in  the  Sedgwick 
iMnsoum,  Cambridge. 

liislriJiiifloK — Cauibridge  (ircensaud  (iii(bgoiinus).      Lower  Chalk  of  Burwcll. 


Til  MA  (Mantellum)  liiMTAXxicA,  sp.  uov.     Plate  VI,  figs.  13^^ — (L 

18-j7.     Lima  elegans,  J.  W.  SaUer.     Quart.  Jouru.  Geol.  Soc,  vol.  xiii,  p.  8.5,  pi.  ii, 

fig.  3  (non  eJegans,  Nilssou). 

Dc^criiiiion. — Shell  moderately  conA'ex,  sub-quadrate  or  nearly  oblong,  very 
oblique.  Antero -dorsal  and  postero-ventral  margins  more  or  less  parallel ;  pos- 
terior margin  rounded.  Ears  of  moderate  size,  with  a  few  ribs  on  the  inner 
portions,  and  with  distinct  growth-lines;  the  anterior  larger  than  the  posterior 
car.  Anterior  area  not  distinctly  limited,  covered  with  ribs  similai-  to  those  on  the 
rest  of  the  valve  but  of  nearly  uniform  size. 

Ornamentation  consists  of  eighteen  main  ribs,  which  are  strong  on  the  anterior 
part  of  the  shell,  but  become  smaller  in  passing  to  the  posterior  end.  At  the 
summit  of  each  main  rib  is  a  narrow,  elevated,  secondary  rib,  and  on  each  side  of 
a  main  ril)  are  two  or  three  similar  Init  rather  small  ribs.  The  secondary  rilis  are 
separated  by  broad  and  rounded  furrows.  The  summits  of  the  secondary  ribs 
are  usually  sharp  and  even,  but  occasionally  slightly  serrate. 

Measuremeutfi: 

Length 19  mm. 

Height 24    „ 

Afflvitirf^. — This  form,  of  which  I  have  seen  one  example  only,  agrees  with  the 
specimen  preserved  in  flint  from  Moreseat  (Aberdeenshire)  which  was  described 
and  figured  by  Salter  as  Ijhna  clrgans  (Xilsson).  That  specimen  is  now  in  the 
Museum  of  Practical  Geology.  Nilsson's'  figure  is  scarcely  sufficient  to  enable  one 
to  determine  the  species,  Init  from  the  recent  illustrations  given  by  Hennig-  it  is 
seen  that  the  British  specimens  differ  from  Lima  elegans  in  being  more  distinctly 
oblong  and  especially  in  having  more  numerous  secondary  ribs. 

1  'Petrif.  Suecana'  (1827),  p.  20,  pi.  ix,  fig.  7;  Hisiuger,  '  Lethsea  Suecica '  (1837),  p.  55,  pi.  xv, 

fig.  10. 

2  Eovis.  Lamelllbr.  i  Nilsson's  '  Petrif.  Suecaua'  (1897),  p.  33,  pi.  ii,  figs.  9,  10,  11.  2t;  Lima 
elegans,  Dujardin  ('Mem.  Soc.  geol.  de  France,'  vol.  ii,  1837,  p.  226,  pi.  xvi,  fig.  1),  is  apparently 
distinct  from  Nilsson's  species. 


LIMA.  3<J 

Type. — In  the  collection  of  ]\Ir.  R.  M.  Brjdone. 

Distribution. — Lower  part  of  the  zone  of  Mifnintfr  (■iii--an(jaiuniii  of  Suaford. 


LiiiA  (Mantellum)  Rkicuexuacui,  CIcinit::,  1839.     i'luLe  VI,  figs.  1  !■(/,  A,  1-J. 

1839.     Lima  Eeichenbachi,  II.  B.  GeiiiUz.     Char.  d.  Schiclit.  ii.  Petref.  des  sik-hs. 

Kreidegeb.,   pt.  1,  p.   24,  pi.   viii, 
fig.  4. 
1841.       —      Eeichenbachii,  i^.  ^i.  ijiimec.     Die  Versteiu.  d.  uord-deutsch.  Kreide- 

geb.,  p.  57. 
1843.       —     Eeichenbachi,  H.  B.   Gcinih.      Die  Versteiu.   vuu  Kieslingswalda, 

p.  23,  pi.  V,  fig.  9. 
184(3.       —  —  A.  E.  Eeuss.     Die  Versteiu.  der  boliiu.  Kreideforuiat., 

pt.  2,  p.  34. 
1847.       —      Eeichenbachii,  A.  d'Orhujmj.    Pal.  Frau9.  Terr.  Crc't.,  vul.  iii,  p.  544, 

pi.  ccccxviii,  figs.  1  —  4. 
1860.       —     Eeichenbachi,  H.  B.  Geinitz.     Das  Quadersaudst.  oder  Kreidegeb. 

ill  Deutschlaud,  p.  190. 
—  —      Eeichenbachii,  A.  d'Ofhiyny.     Prodr.  de  Pal.,  vol.  ii,  p.  166. 

1855.       —  —  G.  Cotteau.     Moll.  Foss.  de  I'Youue,  p.  101. 

1867.       —  —  E.  Giuramjer.     Album  Palcont.  de  la  Sartlie,  p.  19, 

pi.  xxiv,  fig.  5. 
1869.       —     Eeichenbachii,  F.  J.  Pictet  and  G.  Camjnche.     Foss.  Terr.  Crt't.  Ste. 

Croix  (Matur.  Pal.  Suisse, 
ser.  5),  p.  168. 
1872.       —  —  H.  B.   Geinitz.     Das  Elbthalgeb.  iu  SacLseu  (Pal- 

seontographica,    vol.   xx,   pt.  1)^ 
p.  203,  pi.  xliii,  figs.  1,  2. 
1876.       —      Eeichenbachi,  H.  Deiclce.     Tourtia  v.  Miillieiui  a.  d.  Eulir,  p.  27. 
1882.       —      Eeichenbachii,  P.  de  Loriol.     Gault  de  Cosue,  p.  101,  pi.  xiii.  fig.  5. 

Description. — Shell  convex,  oblong,  oblique,  rounded  ventrally;  autero-dorsal 
margin  long,  nearly  straight  and  almost  parallel  with  the  opposite  margin.  Height 
considerably  greater  than  length.  Anterior  area  large,  smooth,  not  depressed. 
Ears  rather  small,  the  anterior  somewhat  larger  than  the  posterior. 

Shell  ornamented  with  from  seven  to  ten  very  strong  ribs,  which  have  romided 
summits  and  are  separated  by  rounded  grooves  of  about  the  same  width  as  the 
ribs.     Small  and  narrow  radial  ribs  are  present  on  both  ribs  and  grooves. 

Measurements  : 

(1)  (2)  (3) 

Length  .  29  .  25  .  21  ram. 

Height  .  35  .  3-A  .  27    „ 

Thickness  .  19  .  U)  .  —    „ 

(1 — 3)  Oenouianiau,  Wiliningtou. 


40  CRETACEOUS   LAMELLIBRAXCHIA. 

liciiKirks. — This  species  is  easily  distiuguislied  b_y  the  very  strong  radial  ribs. 
The  English  sjiecimens,  which  at  present  are  known  from  three  localities  only,  are 
not  well-preserved,  so  that  the  details  of  the  ornamentation  cannot  be  seen  clearly. 

The  occm'rence  of  L.  lieichenbacld  in  England  (from  Wilmington)  was  first 
noted  by  Mr.  Jukes-Browne  in  1898.  The  only  specimens  which  I  have  seen  are 
now  in  the  Museum  of  Practical  Geology  and  the  Sedgwick  Museum. 

Types. — From  the  Lower  Planer  (Cenomanian)  of  Plauen  near  Dresden. 

Distrihutioh. — Upper  Greensand  (zone  of  Peden  aspcv)  of  Warminster. 
Chloritic  Marl  of  Chard.     Cenomanian  Sandstone  of  Wilmington. 


Lima  (]\L\ntellum),  sp.     Plate  VI,  fig.  IG  a,  h. 

BeiiLdiii-". — A  small  specimen  in  the  Museum  of  Practical  Geology  (Xo.  7896) 
is  similar  in  form  and  in  the  general  character  of  its  ornamentation  to  L.  canta- 
hr'ujiensiti  (see  p.  37),  but  the  main  ribs  are  not  so  strongly  developed,  the 
interspaces  are  flatter,  and  the  intermediate  ribs  are  more  prominent.  It  differs 
from  L.  intermedia  in  its  more  distinctly  oblong  form  and  in  the  occurrence  of 
well-developed  intermediate  ribs. 

This  specimen  resembles  closely  the  lowest  of  the  three  figures  referred  io  Lima 
elegans  by  Gucranger.^ 

Distribution. — Chloritic  Marl  of  Chardstock. 


Sab-genus — Ctenoides,  II.  (ind  A.  Adams,  1858  (ex  Klein,  1753). 

('Genera  of  Keceut  Mollubca,'  vol.  ii,  p.  557). 

LiM.\  (('TE\(m.|.>)  \\\v\,  d'Orbiijinj,  1847.      Plate  VI,  figs.  Ma-r.      Plate  VIT,  fig.  1. 

Text-fig.  6. 

1847.     Lima  hai-a,  ^-1.  d'Orhujny.    Pal.  FraD9.  Terr.  Crt't.,vol.  iii,  p.  54(3,  pi.  ccccxix, 

figs.  1 — 4. 
1850.       —         —     A.  d'OrhiijHij.     Proilr.  cle  Pal.,  vol.  ii,  p.  106. 
—         —        —     H.  B.  Gdnitz.    Das  Quadersaudst.  oder  Kreidegeb.  iu  Deulscli- 

laud,  p.  188. 
1855.       —        —     G.Cotteau.     Moll.  Foss.  de  I'Youne,  p.  lOl. 
1867.       —         —     E.  Guerarujer.    Album  Palcont.  de  la  Sartlie.  p.  I'.i,  pi.  xxiv, 

figs.  16,  17. 


'  Album  Paluont.  de  la  Sarthe  '  (1867),  p.  18,  pi.  xxiv,  fig.  1. 


LIMA. 


41 


18G9.     Lima  rapa,  F.  J.  Pldi-t  and  G.  Caminche.      Foss.  Terr.  Crct.  Ste.  Croix 

(Mater.  Pal.  Suisse,  ser.  5), 
p.  168. 

1871.  Radula  (Ctenoides)  rapa,  F.  Stoliczka.      Palseont.  Indica,  Cret.  Fauna 

S.  India,  vol.  iii,  p.  414. 

1872.  Lima  rapa,  H.  B.  GcinUz.     Das  Elbthalgeb.  in  Sachscu  (Palteontograpbica, 

vol.  XX,  pt.  1),  p.  20(i,  pi.  xliii,  fig.  4. 

DesciipHuii  .—  ^\\(A\  moderately  and  regularly  convex,  with  ovate  outline,  nearly 
cqudateral,  considerably  higlaer  than  long,  margins  evenly  rounded.  Umbones 
.^iiiall,  pointed,  close  together.     Apical  angle  about  STf.     Ears  rather  large,  much 


Fio.  G. — Lima  (Ctenoides)  rapa,  d'Orbigny.      Upper  Greensand,  Haldon.      British  Museum,  No.  L.  15616. 

Interior  of  right  valve.     Natural  size. 

higher  than  long,  with  fine  radial  ribs;   the  anterior  ear  larger  tliau  t]i(>  posterior, 
the  latter  with  its  outer  angle  obtuse. 

Ornamentation  consists  of  numerous  fine  radial  ribs  which  diverge  slightly  from 
a  median  or  nearly  median  line  or  sometimes  in  places  from  two  lines.  These  ribs 
are  slightly  raised  and  rounded,  ami  are  separated  by  very  narrow  grooves; 
near  the  anterior  and  posterior  margins  the  ribs  become  nuich  narrower  and 
sharper,  and  may  bear  small  pointed  projections.  The  ribs  are  slightly  wavy 
and  their  course  is  often  more  or  less  sharply  deflected  where  they  pass  the 
growth-lamella?.  Numerous  fine  linear  concentric  ridges  occur,  and  also  some 
growth-lamellue. 

() 


42  *        rRETAf'EOTIH  LAMETJ.IBIUNCHTA. 

Measurements  : 

(I)  (2)  (3) 

Length  .  66  .  43  .  30  nun. 

Height  .  90  .  50  .  41     „ 


'o* 


(1  —3)  Upper  GreensanJ,  Haldou. 


yijfhrifirs. — L.  rapa  is  closely  related  to  L.  flivririrafa  (p.  41)  but  the  valves 
are  less  flattened  and  the  anterior  part  slopes  gi'adually  to  the  margin ;  the  outline 
is  more  regularly  ovate,  and  the  anterior  and  posterior  ribs  are  much  narrower 
than  the  others.     L.  rapa  is  usually  considerably  larger  than  L.  divaricafa. 

Types. — From  the  Cenomanian  of  Coudrecieux  and  Le  Mans. 

Bemarhs. — The  presence  of  this  species  in  English  deposits  appears  to  have 
been  recognised  first  by  the  late  Mr.  C.  J.  A.  Meyer ;  it  was  rocordod  hy  Mr. 
Jukes-Browne  in  189G. 

Dhinbufhm. — Upper  Greensand  of  Haldon.  Cenomanian  (Meyer's  Bed  10)  of 
Dunscombe. 


Lima  (Ctenoider)  tecta,  Goldfuss,  188G.     Plate  VII,  figs.  2,  3. 

1836.  Lima  tecta,  A.  Goldfuss.     Petref.  Germ.,  vol.  ii,  p.  91,  pi.  civ,  fit;.  7. 

1837.  —      FEONDOSA,  F.  Bujardin.     Mem.  Soc.  gt'ol.  de  France,  vol.  ii,  pp.  216, 

227,  pi.  xvi,  fig.  10. 
1839.       —      LAMELLosA,  H.  B.  Gehiitz.     Char.  d.  Schiclit.  u.  Petref.  des  siiclis. 

Kreidegeb.,  pt.  1,  p.  23. 
1841.       —      TECTA,  F.  A.  Bi'imer.    Die  Versteiu.  d.  nord-deutsch.  Kreidegeb.,  p.  58. 
1847.       —         —      A.  d'Orh'ujny.     Pal.  Fraii9.  Terr.  Cret.,  vol.  iii,  p.  547,  pi.  ccccxix, 

figs.  5—8. 
1850.       —         —      H.  B.  Gcinifz.    Das  Quadersaudst.  oder  Kreidegeli.  in  Poutscli- 

land,  p.  188. 

—  —         —      A.  d'Orhigny.     Prodr.  de  Pal.,  vol.  ii,  pp.  166,  247. 

—  —        —      ?,    A.  AUh.       Geogn.-pal.    Beschreib.    Umgcb.    v.    Lemlierg 

(Haidiuger's    Naturwiss.    Abhandl.,   vol.   iii, 
pt.  2),  p.  243. 
?  1852.       —         —      ?,    iJ.  Kner.     Denkschr.  d.  k.  Akad.  Wisseuscli.  Math.-nat. 

CI.,  vol.  iii,  p.  318,  pi.  xvii,  fig.  7. 
1867.       —         —      E.  Gueranger.     Album  Pak'out.  de  la  Sartlie,  p.  19,  pi.  xxiv, 

fig.  11. 
1869.       —        —      E.  Favre.     Moll.  Foss.  de  la  Craie  de  Lemborg,  p.  135. 
1869-70.        -        —F.J.  Pidet  and  G.  Campiche.     Foss.  Terr.  Crct.   St<?.  Croix 

(Mater.  Pal.  Suisse,  ser.  5), 
pp.  168,  170,  173. 
1871.     Radula  (Ctenoides)  tecta,  F.  Stoliczka.     Palocont.  ludica,  Cret.  Fauna 

S.   India,    vol.   iii,    p.   420, 
pi.  XXX,  fig.  12. 


LIMA.  43 

1872.     Lima  tecta,  H.  B.  Geiiiilz.    Das  Elbtlialgeb.  in  Sachsou  (rateontographica, 

vol.  XX,  pt.  1),  p.  206,  pi.  xliii,  fig.  3. 
1877.       —        —A.  Fritsch.     Stud,  im  Gcbieto  der  biihm.  Kreideformat. :  II, 

Weisscnberg.  u.  Maliiitz.  Scliicht.,  p.  130,  fig.  113. 

1894.  —         —      B.  Limdgren.      Mollusk-fauuau  i  Mammillatus  och  Mucronaia 

zonema    (K.    Svcnska  Vet.-Akad.   Handl., 
vol.  xxvi.  No.  6),  p.  43. 

1895.  —         —      F.  Vogel.     Hollandiscli.  Kreide,  p.  18. 

—         —     cf .  TECTA,  E.  Tiessen.     Zeitsclir.  d.  deutsch.  geol.  Gesellsch.,  vol.  xlvii, 

p.  474. 
1898.       —     TECTA,  G.  Miillor.   MoIlusk.Untersen.v.  Braunschweig  u.  Ilsede,  p.  27. 
1902.       —         —      M.  V.   Pdlfij.      Mitthcil.  a.   d.  Jahrb.   d.  k.  ungariscli.   gcol. 

Anstalt,  vol.  xiii,  p.  275,  pi.  xx,  fig.  5. 

Descrijjtion. — Shell  convex,  much  flattened,  sub-ovate,  slightly  oblique, 
considerably  higher  than  long ;  antero-dorsal  part  sloping  steeply  to  the  antero- 
dorsal  margin  which  is  rather  long  and  straightened.  Umbones  small,  only  slightly 
incurved.     Ears  rather  large,  relatively  high,  the  anterior  larger  than  the  posterior. 

Ornamentation  consists  of  numerous  small  radial  ribs,  which  are  rounded,  and 
smooth  or  nearly  smooth.  At  fairly  regular  intervals  the  course  of  the  ribs  is 
interrupted  by  strong  growth-lamelljB,  ventrally  to  which  the  direction  of  the  ribs 
is  sometimes  deflected.  Growth-lamellae,  and  sometimes  ribs,  are  present  on  the 
ears. 

Measurements  : 

Length         ........         27  mm. 

Heiffht 39    „ 

From  the  Cenomauian  (Bed  11)  of  Dunscombe. 


o' 


Affinities. — This  species  is  related  to  L.  dicaricafa  (see  p.  -1-1-),  but  is 
distinguished  by  the  growth-lamellae,  by  the  ribs  not  diverging  from  a  median 
line,  and  by  the  absence  of  the  fine  concentric  ridges.  Lima  essertensis,  de  Loriol,' 
from  the  Urgonian,  is  a  similar  form  but  is  distinguished  by  the  growth-lamellae 
being  more  closely  placed. 

BemarJi-s. — This  species  has  a  considerable  stratigrapliical  range,  extending 
from  Lower  Cenomanian  to  Senonian.  It  has  been  recognised  in  France,  Holland, 
Scandinavia,  Saxony,  Bohemia,  Hungary,  etc.  In  England  it  has  been  found  in 
the  Cenomanian  of  Devon  only,  having  been  discovered  and  identified  by  the  late 
Mr.  C.  J.  A.  Meyer,  and  first  recorded  by  Mr.  Jukes-Browne.  The  examples  from 
the  Arrialoor  Group,  described  by  Stoliczka,  seem  quite  indistinguishable  from  the 
European  forms. 

'  '  Foss.  Corall.  Valaug.  et  Urgoiiien  de  Mt.  Salcve '  (18GG),  p.  83,  pi.  d,  fig.  12  ;  also  in  A.  Favi-e, 
'  Recherch.  gcol.  Savoie,'  vol.  i  (1867),  p.  388,  pi.  c,  fig.  23  ;  Pictet  and  Cauipiche,  '  Terr.  Crct.  St«. 
Croix  •  (1869),  p.  139,  pi.  clxiii,  fig.  7. 


44  CRKTACKOUS    LAiMEM  J  HI!  AXCIl  I  A. 

Types. — From  the  Senonian  of  Macstricht.  D'Orbigny's  specimens  came 
from  the  Cenomanian  of  Lc  Maus  and  from  the  Senonian  of  Tours  and  Loir-et- 
Cher. 

Distribiifion. — Cenomanian  (Bed  11)  of  Dunsconibe. 


Lima  (CrjiNoiDHs)  luvauicata,  Dajardin,  1837.     Plate  V'll,  figs.  4« — d,  5,  <Jn,  b. 

1837.     Lima  divaricata,  F.  Bujardiii.     Mcin.  Soc.  gcol.  Je  France,  vol.  ii,  p.  227, 

pi.  xvi,  fig.  7. 

1840.  —      ARCUATA,  //.   B.    Geinitz.     Cbai".   d.    Scliirht.    u.    Petrcf.   dos    siichs. 

KroiJegeb.,  jjt.  2,  p.  57,  pi.  ix,  fig.  7. 

1841.  —      DIVARICATA,  i^.  J.  iSiimec.     Die  Verstein.  d.  uorJ-deutsch.  Kreidegeb., 

p.  58. 
1850.       —  —  .1.  d'Oi-hujtnj.     Prodr.  de  Pal ,  vdI.  ii,  p.  248. 

—  —      GRANOSA,  /.  de  C.  Sowciiii/  ill  F.  Dixon.     Geol.  Sussex, p.  347  (p.  382, 

ed.  2),  pi.  xxviii,  figs.  24,  25. 
1854.       —  _  /.  Mon-ig.     Cat.  Brit.  Foss.,  ed.  2,  p.  171. 

1859.     Mytilus':'  spectabilis,  J.  Mailer.     Petivf.  der  Aacheu.  Ivroidcf.,  supple- 
ment., p.  10,  pi.  vii,  tig.  10. 

1870.  Lima  granosa,  F.  J.  Pirfef  and  G.  Campiche.     Foss.  Terr.  Crct.  Ste.  Croix. 

(Mater.  Pal.  Suisse,  ser.  5),  p.  169. 

—  —     divaricata,  Fidel  and  Caitipichc.     Ibid.,  pp.  171,  173. 

1871.  Kadula    (Ctenoides)    geanosa,    F.    Stoliczka.      Palieout.    ludiea,    Cret. 

Fauna  S.  India,  vol.  iii,  p.  415. 

—  —  —  divaricata,  Stuliczlca.     Ibid.,  p.  415. 

1872.  Lima    divaricata,    II.    B.    Geinitz.      Das    Elbtbalgeb.    in  Sacliscn    (Pal- 

leontograpbica,   vol.    xx,    i>t.    1), 
p.  205,  pi.  xlii,  tig.  18. 
1889.       —  —  A.  Ftitseli.     Stud,  iin  Gebiete  der  biJhni.  Kreidefoiniiil. : 

IV,  Teplitz.  Scliicht.,  p.  83,  fig.  77. 

—  —  —  E.  Holzapfel.     Die  MoUusk.  Aachen  Kreide  (Paloeon- 

tograpliiea,  vol.  xxxv),  p.  241, 
pi.  xxvii,  fig.  7. 

1897.       —      granosa,  //.  Woodn.     Quart  Jouru.  Geol.  Soc,  vol.  liii,  p.  383. 

1902.       —      divaricata,  M.  p.  Fi'tl/ij.     MKtbeil.   Jahrb.    d.    lc.    uiigarisch.  geol. 

Austalt,  vol.  xiii,  p.  274,  pi.  xx,  fig.  4. 

De.^cript'wn. — Shell  convex,  flattened,  the  anterior  marginal  part  sloping 
steeply,  the  posterior  part  more  gradually  ;  outline  rather  variable,  more  or  less 
ovate  or  aj)proaching  to  oblong,  considerably  higher  than  long,  only  slightly 
unsymmetrical.  Umbones  rather  small,  not  much  incurved.  Ears  relatively 
short  and  high,  not  sharply  limited;   the  antei-ior  larger  than  the  posterior. 

Ornamentation  consists  of  numerous  small  radial  ribs  which  diverge  from  a 
median  or  nearly   median   line  or  sometimes  in  part   from   two  lines  forming   an 


LIMA.  45 

iuverted  W.  Tlie  ribs  are  sliglitly  i-aiscd  and  often  somewhat  wavy  or  irregular, 
especially  near  the  growth-ridg-es.  The  ribs  and  grooves  are  crossed  by  numerous 
concentric  linear  ridges.  The  ribs  are  sometimes  nodular,  the  nodules  having  a 
concentric  arrangement.  At  intervals,  usually  rather  distant  and  fairly  regular, 
distinct  growth-lamellsB  are  seen. 
Measurements  : 

(1)  (2)  (3) 

Length  .  37  .  20  .  22  mm. 

Height  .  51  .  37  .  32    „ 

(1)  Chalk,  Newtimber. 

(2)  B.  mucronata  zone,  Norwicli. 

(3)  H.  ■planus  zone,  Dover. 

Ajjiititles. — See  L.  {Ctomdcs)  nqja  (p.  42)  and  L.  {Clcnoulcs)  tecta  (p.  43). 
7y.  divarlcafa  also  presents  some  resemblance  to  Lima  Uohapfdi,  Hennig,'  found 
in  the  Danian  of  Faxe. 

Bemarls. — This  species  has  hitherto  Ijeen  known  in  England  as  Lima  granosa, 
Sow'erby.  After  making  a  careful  comparison  I  feel  no  hesitation  in  regarding 
it  as  identical  with  the  widely-distributed  L.  dicaricatu,  Dujardin.  This  form  is 
comparatively  rare  in  England,  and  the  part  of  the  shell  near  the  umbo  is  usually 
wanting  or  imperfectly  preserved. 

Type. — From  the  Chalk  (?  Lower  Senouian)  of  Touraiue.  Sowei-by  does  not 
mention  the  locality  or  the  horizon  from  which  he  obtained  Lima  granosa,  and  I  have 
not  succeeded  in  finding  the  type. 

Distrihntion. — Zone  of   Terebratulina  of  Hitchin.     Zone  of  Holastcr  planus  of 
Winchester,  Dover,  and   Cheveley,  Blue  Bell  Hill,   Burham  (?  II.  planus  zone).' 
Chalk  Rock  of  Cuckhamsle3^     Zone  of    Micraster  cor-aitguinum  of  Micheldever. 
Zone  of  Actinocamax  quadratus  of  Salisbury.     Zone  of  Belemnitella  mucronata  of 
Salisbury  and  Norwich. 


Snh-ijrnns — LiMATULA,  N.   r.   W'liod,  1839. 

('  Mag.  Nat.  Hist.,'  new  series,  vol.  iii,  p.  2:33.) 

LiM.\  (LiMATUl..\)  ToMr.ECKiAXA,  d' Orbigiti/,  181-7.    I'latc  VII,  figs.  7a,b,  Sa — c,da,b. 

I8i7.     Lima  Tombeckiana,  A.  (VOrhignij.     Pal.  Frany.  Terr.  Crct.,  vol.  iii,  p.  534, 

pi.  ccccxv,  figs.  13 — 17. 
1850.       —  —  d'Orbigny.     I'rodr.  de  Pal.,  vol.  ii,  p.  82. 

'  '  Bill.  K.  Svon.ska  Vet.  Akad.  Kandl  .'  vol.   xxiv.  No.  7  (1899),  p.  10,  pi.  i.  figs.  1.  2;  Ravn, 
•  MoUusk.  Daumarks  KridUli     I.  Lamollibr. '  (1^02),  p.  lOO,  pi.  ii,  fig.  15. 


46  (.'UETACKOUS    LAMELLl  BRANCllIA. 

?  1854.     Lima  semisulcata,  /.  MorrU.     Cat.  Brit.  Foss.,  ed.  2.  p.  172  (jjarti7n). 
1855.       —      ToMBECKiANA,  (?.  Cutleau.     Moll.  Foss.  de  I'Youue,  p.  100. 
1861.       —  —  P.  de  Loriul.     Aiiim.  Invert.  Foss.  Mt.  Saleve,  p.  95, 

pi.  xi,  fig.  11. 
1869.       —  —  P.    de   Loriol   and    V.    GiUu'ron.      Urgon.    infer,    de 

Landerou,  p.  I'J,  pi.  i,  fig.  17. 

—  —  —  F.  J.  Pictet  and  G.  Campiche.     Foss.  Terr.  Cret.  Ste. 

Croix  (Matt'r.  Pal.  Suisse,  ser.  5),  p.  148. 
1871.     Eadula  (Limatula)  Tombeckiana,  F.  Stoliczka.     Palajont.  ludica,  Cret. 

Fauna  S.  India,  vol.  iii,  p.  414. 

—  Lima  Tombeckiana,   W.  A.  Ooster.     Protozoa  Helvetica,  vol.  ii,  pp.  104, 

123,  140. 
1883.       —  —  W.  Keepintj.     Foss.,  etc.,  Neoc.  Uinvare  and  Brick- 

hill,  p.  111. 

Description. — Shell  oval,  inflated,  higher  than  long,  produced  a  little  more 
anteriorly  than  posteriorl3\  Umbones  rather  small,  close  together.  Ears  equal. 
Margins  of  valves  roitnded,  the  posterior  with  a  greater  curvature  than  the 
anterior. 

Ornamentation  consists  of  from  13  to  16  strong,  rounded  or  slightly  keeled 
ribs  separated  by  narrow  grooves.  The  ribs  are  confined  to  the  median  part  of 
the  shell,  and  the  anterior  and  posterior  parts  are  without  ribs.  The  ribbed  portion 
is  not  quite  symmetrically  placed,  the  anterior  smooth  portion  being  rather  larger 
than  the  posterior  smooth  portion.  Very  fine  concentric  ridges  are  present  on  the 
shell,  and  may  form  scale-like  projections  where  they  cross  the  ribs. 

Measurements  : 

(1)  (2)  (1.)  (5)  ((-) 

Length  0  9  8  8  7  11      mm. 

Height  12  11  12-5        13  lU  15-5    „ 

(1 — 5)  Hytlie  Beds,  Court-at-Street. 
((3)  Lower  Greensand,  Brickhill. 

Afl'udtles. — Some  specimens  of  L.  Tomhcckiana  approach  very  closely  L. 
Fittoid  from  Blackdown  and  Haldon  (sec  p.  48),  and  it  is  quite  possible  that  the 
latter  is  only  a  local  variety  of  the  former  since  some  examples  found  in  the  Upper 
Greensand  of  Charmouth  and  Potterne  (Plate  VII,  fig.  10)  seem  indistinguishable 
from  L.  TombecJciana.  As  a  rule  L.  Tombeckiana  differs  from  L.  Fittuni  in  having 
the  ribbed  part  of  the  shell  more  nearly  symmetrical  in  position,  in  the  shell  being 
rather  longer  and  rather  more  convex  with  the  umbonal  part  more  j)ointed,  and 
in  the  ribs  being  more  rounded. 

L.  Tomheclciana  differs  from  /;.  semisulcata,  Nilsson,  in  being  smaller,  relatively 
longer,  less  symmetrical,  and  with  the  umbonal  part  more  pointed.  In  this  con- 
nection, however,  it  should  be  noted  that  Hennig  ^  considers  that  specimens  which 
1  Eevis.  Lamellibr.  i  Nilsson'a  'Petrific.  Suecana'  (1897),  p.  29. 


LIMA.  47 

he  lias  seen  from  the  Lower  Greensand  of  Atlicrfield  and  Blacksransf  belono-  to 
L.  semisulcata.  L.  TomhecJciana  also  resembles  L.  svprajuretisis,  Contejean,^  found 
in  the  Upper  Jurassic. 

T]ipe!(. — D'Orbigny  does  not  give  the  locality  of  the  type,  but  says  that  he 
obtained  specimens  from  the  Neocomian  of  Neuchatel,  Auxerre,  Saint  Sauveur,  etc. 

DtNtrihiition. — Hytlie  Beds  of  Court-at-Stroet  near  Lympne.  Lower  Greensand 
of  Brickhill.     Teal1)y  Tiiinestone  (zone  of  /?.  hnnisi-icpinils)  of  Nortli  Willingham. 


TjIma  (liTMATrLA)  DuPiNMANA,  r/'O/'A/r/y/y,  1847.     Plate  VII,  figs.  11  r/ — r. 

?  184-5.     Lima  semisulcata,  E.  Forbes.      Quart.  Journ.   Geol.  Soc,  vol.  i,  p.  248 

(non  semisulcata,  Nilssou). 
1847.     Lima  Dupiniana,  A.  (VOrhigny.     Pal.  rran9.  Terr.  Crct.,  vol.  iii,  p.  535, 

pi.  ccccxv,  figs.  18 — 22. 
18.50.        —  —  d'Orhigny.     Prodr.  de  Pal.,  vol.  ii,  p.  81. 

1854.  —  —  J.Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  171. 

1855.  —  —  0.  Cotteau.     Moll.  Toss,  de  rTonne,  p.  100. 
1865.       —             —  H.  Coqnand.     Mon.  Aptien  de  I'Espagne,  p.  151. 
1869.       —             —             F.  J.  Pictet  and  G.  Campiche.      Foss.  Terr.  Cret.  Ste. 

Croix  (Mater.  Pal.  Suisse, 
ser.  5),  p.  150. 
1871.     Radula  (Limatula)  Dupiniana,  F.  StoUczka.       Pateont.    Indica,   Cret. 

Fauna  S.  India,  vol.  iii,  p.  414. 

Non  1883.     Lima  Dupiniana,  A.  Frllsch.     Stud,  im  Gcbiete  der  biihin.  Kreideforniat. : 

III,  Iscrschicliteu,  p.  112,  fig.  81.  ^ 

BpscripHon. — Shell  oval,  moderately  convex,  much  higher  than  long,  nearly 
equilateral,  with  the  posterior  margin  more  convex  than  tlie  anterior.  Umbones 
very  small,  pointed,  close  together.     Ears  unequal. 

Ornamentation  consists  of  from  ten  to  fourteen  very  narrow  radial  ribs, 
usually  with  sharp  summits,  separated  by  broad  rounded  grooves.  Tlic  anterior 
and  posterior  parts  of  the  shell  arc  without  ril)s,  and  tlio  posterior  part  is  con- 
siderably larger  than  the  anterior.     Very  fine  concentric  ridges  are  present, 

Moafurri'mfiifii : 

(1)  (2) 

Length  .  11  .  8     mm. 

Height  .  21  .  14-5    „ 

(1)  Tealby  Limestone,  North  Williugliaiu. 

(2)  Ferniginous  Sands,  ShanklLn. 


•  '  Kimmcrid.  de  Monflx'liard  '  (1859),  p.  351.  pi.  xxvii,  fig.  9  ;  de  Loriol  and  Cotteau, '  Portland, 
de  I'Yonne  '  (1868),  p.  20.5,  pi.  xiv,  figs.  1,  2. 


48  rRETAC'EOUS    LAMELLTBT^AXriTTA. 

Affinifie.^. — This  species  is  easily  distinguished  from  L.  Tomhecliana  (see  p.  45) 
by  its  rehitively  higher  and  less  inflated  form,  l)y  the  narrow  ribs,  and  by  the  less 
symmetrically  placed  ribbed  area. 

In  its  narrow  ribs  L.  Dtipiniana  resembles  L.  svhcvrjji'ilatrrnlift,  d'Orbigny  (see 
page  49)  but  the  ribs  in  the  latter  arc  distributed  over  the  groatoi-  ]iai-t  of  the 
shell  and  are  more  widely  separated  and  more  numerous. 

The  specimens  referred  to  L.  semimdcata  by  Forbes  are  poorly  i)rescrved,  Init 
probably  belong  to  this  species. 

Types. — From  the  Neocomian  of  MaroUes  (Aube)  and  Saint  Sauveur  (Yonne). 

Distribution. — Tealby  Limestone  (zone  of  li.  hrvnsvicensis)  of  North  Willing- 
ham.  Ferruginous  Sands  of  Slinnklin.  Athcrfiold  Beds  of  "Rcdliill.  TTytlio  Beds 
of  Hythe  (.//-/'•  Topley). 


Lima  (Limati  la)  Fittoni,  <VOyhi,jmj,  1850.     Plate  VII,  figs.  12—14,  15  a—c. 

183C.     Lima,  semisdlcata,  J.  de  C.   Sowerhy.     Trans.  Geol.  Soc,  ser.  2,  vol.  iv, 

pp.  336,  359  (not  129,  158),  j.!. 
xi,  fig.  10. 
1850.       —      Fittoni,  A.  (TOrhifjny.     Prodr.  de  Pal.,  vol.  ii,  p.  82. 
1854.       —      sEMi.suLCATA,  /.  Morris.     Cat.  Brit.  Pos-s.,  cd.  2,  p.  172  (^partim). 
1869.       —  —  J^.  .7.   PIrtrl  and  O.  Cnnpichi'.     Foss.  Terr.   Crut.    Slo. 

Croix  (Mater.  Pal.  Suisse, 
ser.  ■>),  p.  166  {partim). 

Descrijdion. — Shell  oval,  moderately  convex,  higher  than  long,  slightly  in- 
equilateral, with  rounded  margins,  the  posterior  being  more  convex  than  tlie 
anterior.     Umbones  small,  close  together.     Ears  equal. 

Ornamentation  consists  of  from  13  to  15  radial  ribs  with  sharp  summits, 
separated  by  narrow  grooves.  Pointed  projections  are  present  on  the  summits 
of  the  ribs,  especially  near  the  ventral  border  of  the  shell.  Tlie  auterioi'  and 
posterior  parts  of  the  shell  are  without  ribs.  The  riljbed  area  is  nnsymmetri- 
cally  placed,  and  the  anterior  smooth  jiart  of  tlie  shell  is  considerably  smaller 
than  the  posterior  part.  Fine  concentric  ridges  are  seen  on  well-preserved 
specimens. 

Measurements  : 

(1)  (2)  (3)  (4)  (r,) 

Length      .10  9  8  8  7 

Height      .       IG         14         14         13         12-5 
(1,  3 — 7)  Upper  Greensand,  Haldou. 

(2)       „  „  Blackdown. 


(••>) 

(7) 

7 

()  nnn 

12 

10     „ 

LIMA.  49 

Affinities. — This  form  was  referred  hj  Roworby  (in  Fitton)  to  the  Senonian 
species  L.  >temisHlcata,  Nilsson,^  but  has  been  regarded  by  most  later  writers  as 
distinct  from  that  species,  and  was  named  L.  Fiffoni  by  d'Orl)ignj'-. 

L.  Fitfoni  differs,  as  a  rule,  from  L.  semisulcata  in  its  smaller  size,  and  in  having 
the  ribbed  area  less  extensive  and  much  more  asymmetrical  in  position,  though 
occasionally,  however,  it  is  nearly  symmetrical.  It  also  appears  to  differ  in 
having  a  relatively  shorter  hinge-line  and  less  equilateral  form. 

For  the  relation  of  L.  Fiffoni  to  L.  TumhecHana  see  p.  46. 

Tyfo. — The  type  is  Lima  aomisnlcMfa,  Sowerby  {iion  Nilsson)  from  the  Upper 
Greensand  of  Blackdown.  A  specimen  in  the  Bristol  Museum  is  regarded  as  the 
type,  but  does  not  agree  very  well  with  the  figure. 

Distnbution. — Upper  Greensand  (zone  of  Schloenhachia  rostrata)  of  Blackdown 
and  Haldon.  Cenomanian  of  Axmouth  (Bed  12  of  Meyer),  Dunscombe  (Bed  10), 
and  Pinhay. 


Lima  (Limatula)  suBiEauiLATEiJALi.s,  iVOrhigny,  1847.     Plate  VII,  figs.  IGa, //,  17. 

1847.     Lima  sub^siquilateralis,  A.  d'Orhigny.     Pal.  Fran9.  Terr.  Cret.,  vol.  iii, 

p.  558,  pi.  ccccxxiii,  figs.  1 — 5. 
1850.       —  —  d'Orhigny.     Prodr.  de  Pal.,  vol.  ii,  p.  167. 

1870.  —  —  F.  J.  Pidet  and  G.  Campiche.     Foss.  Terr.  Cret. 

Ste.  Croix  (Mater.  Pal.  Suisse, 
ser.  5),  p.  169. 

1871.  Radola  (Limatula)   s0b.«;quilateealis,  F.  Stoliczka.     Palseont.  Indica, 

Cret.  Fauna  S.  India,  vol.  iii, 
p.  415. 

Description. — Shell  oval,  or  rounded  oblong,  pointed  at  the  umbones,  nearly 
equilateral,  about  twice  as  high  as  long,  of  moderate  convexity.  Anterior  margin 
less  curved  than  the  posterior.     Ears  equal,  smooth,  with  pointed  ends. 

Ornamentation  consists  of  about  20  very  narrow  ribs  separated  by  jjroad, 
slightly  concave,  interspaces  which  are  crossed  by  growth-lines.  Ribs  are  absent 
near  the  anterior  and  posterior  mai-gins. 

Measurements  : 

Length  .  .  .  10  mm. 

Height  .  .  .  P->    „ 

Upper  Greensand,  Warminster. 

Affinities. — See  TAma  Diqnniana  (p.  48)  and  Limn  sj).  (p.  52). 
Eemarks.—l  have  seen   only   two    English  examples  of  this  species,  both  of 

'  For  references,  see  p.  .'>1 .  footnote. 

7 


50  CRETATEOT^S    E.\  ^FEI-l-II'.H  AXCTTTA. 

wliicli  ai'(>  iiinro  ov  less  imperfect,  l)ut  after  an  examination  of  specimens  of 
L.  suhasqnilateralis  from  Le  Mans  in  the  Museum  of  Palfeontology  at  Paris  I  am 
inclined  to  refer  them  to  that  species.  Tn  the  specimens  from  Le  Mans  the 
number  of  rilxs  is  sometimes  greater  than  is  shown  in  D'Orbigny's  figure,  also  the 
ears  may  be  less  sharply  separated  from  the  valve,  and  in  one  case  the  hinge-line 
was  seen  to  be  relatively  longer. 

Types. — From  the  Cenomanian  of  Le  Mans.  The  specimens  here  figured  are 
in  the  British  Museum. 

Distnhution. — Upper  Greensand  (zone  of  Pecten  asppr)  of  Warminster. 


Lima   (Limatit.a)  decussata,  Goldfuss,  1836.     Plate  A^TT.  figs.  ISo, /',  10,  20^/, /*. 

1836.  Lima  decussata,  A.  Goldfuss.     Petref.  Grerui.,  vol.  ii,  p.  01,  pi.  civ,  fii^'.  5. 

1837.  Plagiostoma  granulatdm,  W.  Hisimjer.     Lethtea  Suecica,  pi.  xv,  fig.  7. 
1841.     Lima  decussata,  F.  A.  Bijmer.     Die  Verstein.  d.  nortl-deutsch.  Kreidegeb., 

p.  55. 
184G.       —  —  A.  E.  Revss.      Die  Verstein.  dor  bohm.  Kreidefoi-mat., 

pt.  2,  p.  32,  pi.  xxxviii,  fig.  15. 
1847.       —     SEMisuLCATA,  J.  Miillcr.     Petref.  der  Aachen.  Kreidef.,  pt.  1,  j).  33. 
1850.       —     DECUSSATA,  A.  cVOrbigny.     Prodr.  de  Pal.,  vol.  ii,  p.  248. 

—  —     SEMISULCATA,  if.  Kner.     Verstein.  v.   Lemberg   (Haidinger's  Natur- 

wiss.  Abhandl.,  vol.  iii,  pt.  2),  p.  29. 

—  —     DECUSSATA,  A.  AJfJi.     Geogn.-palEeont.  Bescbreib.  v.  Lemberg   (Haid- 

inger's Naturwiss.  Abhandl.,  vol.  iii,  pt.  2), 
p.  241. 

—  —     SEMISULCATA,  AWi.     Ibid.,  p.  242. 

1863.       —     DECUSSATA,  A.  V.  Stromheck.     Zeitschr.  d.  deutsch.  geol.  Gesellsch., 

vol.  XV,  p.  151. 
?  —         —  —  S.  Placketko.     Das   Becken    von   Lemberg    (Jahresb.  d. 

k.   zweite  Ober-Gymnas.   in  Lemberg), 
p.  20,  pi.  i,  fig.  19. 
1866.       —  —  K.  A.  ZUtel.     Die  Bivalven  d.  Gosaugeb.  (Doukschr.  d. 

k.  Akad.  d.  Wissensch.  Wien,  vol.  xsv), 
pt.  ii,  p.  105,  pi.  xvi,  fig.  4. 
18G9.       —  —  E.  Favre.     Moll.  Foss.  de  la  Craie  de  Lemberg,  p.  136. 

1870.  —  —  F.  J.  Bidet  and  G.  Campkhe.      Toss.   Terr.  Crot.  Ste. 

Croix  (Matc'r.  Pal.  Suisse,  ser.  5), 
p.  174. 

1871.  Eadula  (Limatula)   decussata,   F.  SioViczha.      Palseont.    Indica,   Cret. 

Fauna  S.  India,  vol.  iii,  p.  415. 

1888.  Lima  decuss.'v.ta,  A.  Peron.     L'Hist.  du  Terr,  de  Craie,  p.  145,  pi.  i,  fig.  18. 

1889.  —  —  E.   Hohaffel.      Die  Mollusk.  Aachen.   Kreide  (Pal«on- 

tographica,  vol.  xxxv),  ji.  242,  pi.  xxvii, 
fig.  4. 


LIMA.  51 

1000.     Lima  i>ecvssata.,  C.  Gagel  and  F.  Kaunhowen.    Jalivb.  d.  k.  preussisch.  gcol. 

Landesanst.  fiir  1891»,  p.  232. 
1902.       —  —  /.  F.  J.  Itacn.     Mollusk.  i  Danmarks  Kridtafl.  :  I.  Lam- 

ellibr.   (K.  Dauske  Vid.  Selsk.  Skrift., 
6  Eajkke,  nat.  og.  math.  Afd.,  vol.  xi), 
p.  9G,  pi.  ii,  fig.  11. 
—  —  —  A.  Wollemann.     Fauna  d.  Liineburg.  Kreidc  (Abhandl. 

d.  k.    preussiscli.    gcol.    Laudesanst., 
N.  F.,  Heft  37),  p.  .57. 

Description. — Shell  inflated,  ovate  oi*  rounded-oblong,  nearly  equilateral.  Um- 
])ones  small.     Bars  rather  small,  nearly  equal. 

Ornamentation  consists  of  numerous  sharp  ribs,  sej^arated  by  narrow  grooves. 
The  ribs  become  less  distinct  on  the  anterior  and  posterior  parts  of  the  shell. 
Numerous  fine  concentric  ridges  occur,  and  sometimes  give  rise  to  a  tubercular 
appearance  on  the  sunamits  of  the  larger  ril^s. 

Measurements  : 

(1)  (2)  (3)  (4)  (5) 

Length       .10  9  7  7  6-5  mm. 

Height       .  13-5  12  11  lO'o  9-5    „ 

(1,  2,  4,  5)  A.  quadratus  zone,  East  Haruham. 

(3)  Uintacrinus  band,  Devizes  Road,  Salisbury. 


Affinities. — L.  semisnlcata,  Nilsson,'  is  distinguished  from  L.  decussuta  by  the 
ribs  being  limited  to  the  median  part  of  the  shell,  and  hj  the  relatively  higher 
valves. 

Peron  thinks  that  L.  prdinafa,  d'Orljigny,  may  be  only  a  variety  of  L.decussata. 
It  appears  to  differ  from  the  latter  in  having  the  ribs  more  tubercular  and  usually 
fewer  in  number. 

Ti/pe. — From  the  Senonian  of  Rinkerode,  near  Miinster. 

Distribution. —  Uintacrinus  band  of  Devizes  Road,  Salisbury.  Zone  of  Actino- 
caniiLc  quadratus  of  East  Ilarnham  and  Ashley  Hill.  Zone  of  IJeleuniilella  mucronata 
of  Clarendon. 


Li.M.\  (LiM.\TLi,.\)  wiNTONENSis,  sp.  nov.     Plate  VII,  figs.  21  (/,//,  22 'f — d. 

Description. — Shell  inflated,  ovate,  nearly  equilateral,  pointed  dorsally. 
Ornamentation  consists  of  15  or  10  strong,  rounded  ribs  on  the  median  part  of 
the  valve  only.     The  ril)s  are   separated  l)y  very  narrow  grooves,  and  bear  many 

1  'Petrif.  Suecaua'   (1827),  p.   2.5,  pi.  i.\,  fig.  3;  Hcunig,  Kevis.    LanicU.  i  Nilssou's   '  Petrif . 
Suecana'  (1897).  p.  28,  i-l.  ii,  fig.s.  II,  17. 


52  UKETACKOUS    J.AMKLI.I  liKAiXCHlA. 

strong  ridges  placed  concentrically  and  regularly.  Below  a  growth-ring  the 
ridges  are  sometimes  situated  more  closely  together.  One  or  two  ril)s  at  the 
margins  of  the  ri])l)ed  area  are  rather  smaller  than  the  others.  The  parts  between 
the  ribl)ed  area  and  the  anterior  and  posterior  margins  of  tlic  valve  arc  sniooth 
except  for  faint  growth-lines. 


Memurements  ; 

(1) 

(2) 

(3) 

W 

(3) 

Tjcngth 

7 

6 

5-5 

5-5 

5  mm. 

Height 

10 

8 

8 

7-5 

7    „ 

(1)  Chalk,  Claytou. 
(2 — 5)  A.  (piadraiiis  zoao,  Winchester. 

Ajjijutics. — This  species  is  distinguished  from  L.  decussate  (p.  50)  by  being 
more  pointed  dorsally,  by  having  fewer  ribs,  which  also  are  rounded  and  confined 
to  the  median  part  of  the  valve,  and  by  the  strong  ridges  which  extend  across  the 
ribs. 

In  outline  this  species  resembles  Lima-  jH'ctiiinhi,  d'Orbigny,'  l)ut  differs  in 
having  fewer  ribs,  in  the  absence  of  ribs  on  the  anterior  and  posterior  parts  of  the 
valves,  and  in  the  ribs  not  being  carinated  and  having  ridges  across  them 
instead  of  tubercles  at  the  summits. 

This  species  resembles  closely  the  form  figured  by  Geinitz^  as  L.  isenmalcalu, 
Nilsson. 

Distribution. — Zone  of  Actinocama,r  ([iiadratux  of  Winchester.  Upper  Chalk 
(probably  zone  of  Micraster  cor-tcstndinarium)  of  Kenley. 


LiJiA  (^Limatula),  sp.     Plate  Vil,  fig.  2'S(i,  h. 

Description. — Shell  inflated,  oval,  nearly  equilateral.      Umbones  small.     Hinge- 
line  relatively  long.     Ears  not  sharply  limited,  nearly  equal. 

Ornamentation  consists  of  about  20  narrow  ribs,  separated  by  very  broad  and 
shallow  interspaces  in  which  very  fine  radial  ribs  may  be  seen.     The  ribs  anterior 
to  the  median  line  are  closer  together  and  rather  stronger  than  the  others.     On 
the  parts  of  the  valves  next  to  the  ears  ribs  appear  to  be  absent. 
Measurements  : 

Length  ........  ()■.">  nun. 

Height 1'        „ 

'  'Pal.  rran9.  Terr.  Cret.,'  vul.  iii  (1847),  p.  572,  pi.  ccccxxvii,  tigs.  15— lU. 
=  '  Das  Elbthalgeb.  iu  Sachscu,'  pt.  2  (1873),  p.  53,  pi.  xvi,  fig.  14. 


LIMA.  53 

Affinities. — In  the  churiictfi'  of  its  onianieiitation  this  form  ivse-iiihlos  Lima  unh- 
.ri/uilaferalis,  d'Orbigny  (see  p.  I'Jj,  fVoni  the  Cenonianian  oi  JjcMaiis,  but  tlie  shell 
is  not  so  high,  is  less  pointed  in  (he  umbonal  region,  and  has  a  longer  hinge-line. 

In  outline  this  form  resembles  the  exaiii|ilc  figiir(>d  b_y  Ravn  '  as  Liiiin  Fmrli- 
hammeri,  von  Hagenow,  Imt  possesses  a  miirh  largei'  iiumlHi'  (if  ribs. 

Beniarh. — I  have  seen  one  specimen  only,  which  is  in  Di'.  Blackinore's 
collection. 

Dtstributioii. — Zone  of  Bdemiiiidla  laucivnatu  of  Clarendon  (Salisbury). 


Siih-ijciins — LlllKA,    Tf.  (1.  Ih-iniit,  is.')!. 

(' Italiens  Tertiiir-GL'liililc  uiid  ilircii  Uigauisehe  Eiusuliliisse,'  p.  115.^ 

Lima   (IjImea?)  ro.MrosiTA   (Soiccrhi/),  18o(i.     Plate  VII,  &gs.  2-ia,  b,  2bii,  b,  26. 

1836.     Pecten  compositus,  /.  de  C.  Sowerhy.     Trans.  Geol.  Soc,  ser.  2,  vol.  iv, 

l)p.  241,  342,  pi.  .xvii,  fij,'.  20. 
1847.     LiUA  cEHOMAHKasia,  A.  d'Orhitjny.     Pal.  Fran^.  Terr.  Crut.,  vol.  iii,  ji.  552, 

pi.  ccccxxi,  figs.  11 — 15. 
1850.       —  —  d'Orhujnij.     Prodr.  de  Pal.,  vol.  ii,  p.  167. 

1867.       —  —  E.  Gui'nnuji-r.      Albiiui  Pak'ont.  de  la  Sartliu,  p.  19, 

pi.  xxiv,  figs.  4,  P. 
1870.       —  —  F.  J.  PicM  and  G.  Campkhe.     Foss.  Terr.  Cri-t.  Stc. 

Croix  (Matt'r.  Pal.  Suisse, 
ser.  5),  pp.  161,  168.  « 

F.  Sf(iUci:l-a.     Palicout.  ludica,  Crct.  Fauna  S.  India, 

vol.  iii,  1).  416. 
li.  Wuidinuller.    Jahrb.  d.  k.  proussisfb.  geol.  Landes- 
anst.  fiir  1881,  pp.  24,  29. 


1871. 

LiMEA 

— 

1882. 

Lima 

— 

Measurehwidii : 

(1) 

(2) 

Length 

12-5 

11 

Heiofht 

L5 

l;3 

(3)  (i)  (5)  (C) 

l(t  9  9  8     mm. 

II-:)        l()-25      10  9-.5    „ 

(1,  3  —  6)  Upper  Greeusuud,  Warminster. 
(2)  Rye  Hill  Sand,  Maiden  Bradley. 

Affinities. — This  form  is  closely  related  to  Lima  ijranuhta  (sin;  hvlow).  The 
oi-namentation  appears  to  have  been  similar  in  both  cases,  but  in  L.  compusila  the 
scale-like  spines  on  the  ribs  are  much  less  perfectly  preserved  and  usually  appear 
as  tubercles  only.     In  L.  composita  the  shell  appears  to  be  rather  less  obli(|ue  and 

1  '  MoUuskerue  i  Daumarks  Kridtaflej.     1.  Laiuellibr.'  (1902),  p.  97,  pi.  ii,  fig.  12. 


54  CRETArEOUS    LAMELLIRRAXriIIA. 

more  iieaily  cnuilatrral  tlian  in  />.  grdiiidutit ;  the  height  is  also  slightly  greater 
and  the  iimbones  rather  more  prominent ;  the  ribs  appear  to  be  narrower  and  to 
have  sharper  summits.  The  smaller  convexity  of  L.  compusita  mentioned  by 
d'Orbigny  does  not  seem  to  be  constant. 

liemarlcs. — An  examination  of  the  type  of  I'ccfoi  rumpo!<ifnK,  8owerby,  shows 
that  it  is  an  example  of  this  species  (see  Vol.  I,  p.  188,  footnote),  and  con- 
sequently the  specific  name  composita  must  take  the  place  of  cenomanenKis. 

The  French  examples  Aviiich  I  have  seen  are,  on  the  average,  larger  than  the 
English. 

Tijin'S. — The  type  of  L.  cciiomanensis  came  from  the  Cenomanian  of  Le  Mans. 
The  type  of  Fectcn  cuirqHmtm  is  in  the  Bristol  Museum ;  it  is  labelled 
"  Blackdown  "  but  is  not  siliceous  and  is  more  probably  from  AVarminster. 

DistrUndion, — Upper  Glreensand  (zone  of  Pccteii  as^wr)  of  Warminster.  Rye 
Hill  Sand  of  Maiden  Bradley.  I  have  not  seen  the  specimens  recorded  in  the 
Memoirs  of  the  Geological  Survey  from  the  zones  of  Schlienbachia  variait.i  and 
Uolanter  suhglohosus  of  Hunstanton. 


Lima  (Limea?)  granulata  (Nilsson),  1827.     I'latL' A'll,  figs.  27rt — c,28,29a,b. 

1827.     Plagiostoma  geanulatum,  S.   Nilssoii..      Petrif.    Suecaua,   p.   '20,  pi. 

fig.  4. 
1833.  —  GRANULosuM,   S.    Woodwcinl.      Geol.    Norfolk,   pp.    48,    51, 

pi.  V,  fig.  26. 

1836.  Lima  granulata,  A.  Goldfuss.     Petref.  Germ.,  vol.  ii,  p.  89,  pi.  eiii,  tig.  5. 

1837.  Plagiostoma  granulatum,  W.  Hisinger.     Lethtea  Suecica,  p.  54  (not  the 

figure,  pi.  XV,  fig.  7). 

1841.  Lima  uuricata,  i^.  ^J.  iWmt'r.     Die  Versteiu.  d.  uord-deutscli.  Kreidegeb., 

p.  55. 

1842.  —      granulata,  F.  v.  Hngenoiv.     Neues  Jahrb.  fiir  Miu.,  etc.,  p.  555. 

1846.  —  —  A.  E.  Eeuss.     Die  Versteiu.  der  biihrn.  Kreideformat., 

pt.  2,  p.  32,  pi.  xx.\viii,  fig.  21. 

1847.  —  —  A.  d'Orhignij.     Pal.  Fran9.  Terr.  Cret.,  vol.  iii,  p.  570, 

pi.    ccccxxvii,    figs.    5 — 9.      (Named 
L.  gratiom  on  plate.) 

1850.  —  ~  d'Orbigny.     Prodr.  de  Pal.,  vol.  ii,  p.  248. 

1851.  —      pseudocabdium,  inflata  et  dentata,  J.  Midler.    Petref.  der  Aaclien. 

Kreidef.,  pt.  2,  jip.  67,  68. 
1855.       —       GRANULATA,  G.  Gotteau.     Moll.  Foss.  de  rYonne,  p.  102. 
1870.       —  —  0.  Schhdcr.     Neues  Jahrb.  fiir  Min..  etc.,  p  950. 

—  —  —  F.  J.  Field  and  G.  Camj'ichc.     Foss.  Terr.  Cret.  Ste. 

Croix   (Mater.  Pal.  Suisse, 
ser.  5),  p.  170. 


?    _ 
1881 


LIMA.  55 

187G.     LiM/r,A   ORANULATA,    D.    Brauns.      Zcitsdir.    f.    d.    gesauimt.   Naturwiss., 

vol.  xlvi,  p.  386. 
Lima  qranulata,  H.  Beiclce.     Die  Tourtia  von  Miilhcim  a.  d.  Ruhr,  p.  27. 
LiMEA  GRANULATA,  K.  A.  ZiUeJ.     Handh.  d.  Palceont.,  vol.  ii,  p.  27. 

1888.  Lima  granulata,  A.  Peron.     L'HLst.  Terr,  de  Craie,  p.  147. 

1889.  LiMEA  ORANULATA,   O.   Griepenhfrl.      Senon.  von  KiJnigslutter   (Palseont. 

Abliandl.,  vol.  iv),  p.  41. 

—  Lima  granulosa,  E.  Uuhapfd.     Die  Mollusk.  Aachen.  Kreide  (Palffion- 

tographica,  vol.  xxxv),  p.  239,  pi.  xxvii, 
fig.  6. 

—  —      guanulata,  a.  Fritsdt.     Stud,  im  Gobicte  der  bohm  Kreideformat. : 

IV,  Teplitz.  Schioht.,  p.  83,  fig.  76. 

1893.  —  —  Fritsch.     Ibid.,  V,  Priesener  Schicht.,  p.  100. 

1894.  —  —  B.  Lnndgren.     Molluslc-faiinaii  i  Mfinuiilll.  och  Mucron. 

zonerna(K.  SveuskaVet.-Akad.  Handl., 
N.  F.,  vol.  xxvi.  No.  6),  p.  42. 

1897.  —  —  A.  Hennig.     Eevis.  Lamell.  i  Nilssou's 'Petrific.  Suecana' 

(K.  Fys.  Siill.sk.  i  Lund.  Hand!.,  N.  F., 
vol.  viii),  p.  26,  pi.  ii,  figs.  6 — 8. 

1898.  —  —  G.  Mailer.     Mollusk.  d.  Untersen.  v.  Braunschweig  u. 

Ilsede  (Abhandl.  d.  k.  preussisch.  geol. 
Landesanst.,  N.  P.,  Heft  25),  p.  29,  pi.  iv, 
fig.  6. 

1901.  —  —  A.  Wollrmann.    Jalirl).  d.  k.  preussisch.  geol.  Landesanst. 

fiir  1900,  vol.  xxi,  p.  16. 

1902.  —  —  Wollemanii.   Liineburg.  Kreide  (Abhandl.  d.k.  preussisch. 

geol.  Landesanst.,  N.  F.,  Heft  37),  p.  57. 
—         —  —  J.  P.  J.  Ravn.     Mollusk  i  Danmarks  Kridtaflej.  I.  (K. 

Danske  Vid.  Selsk.  Skrift.,  6  Ecekke, 
nat.  og.  math.  Afd.,  vol.  xi),  p.  101. 

Non  1837.       —  —  F.  Bujanlin.     Mem.  Soc.  geol.  de  France,  vol.  ii,  p.  226, 

pi.  xvi,  fig.  4  (=  L.  Meslei,  Peron,  1888). 

Description. — Sbell  very  convex,  oval,  sliglitly  ol)]ique,  with  rounded  outline ; 
height  a  little  greater  than  length.  Apical  angle  very  large.  Umbones  small, 
incurved,  close  together.  Ears  of  moderate  size,  nearly  equal,  rather  low  aiid 
long,  with  a  few  spiny  ribs. 

Ornamentation  consists  of  numerous  (usually  from  22  to  24)  strong  ribs  with 
sharp  summits,  separated  by  narrow  furrows.  Each  rib  bears  three  rows  of  scale- 
like spines,  one  row  being  at  the  summit  and  one  on  each  side.  The  spines  are 
placed  near  together,  at  regular  intervals,  and  curve  upwards  from  the  surface  of 
the  shell,  the  terminal  parts  sometimes  becoming  quite  erect.  The  middle  row  is 
rather  larger  than  the  rows  on  the  sides.  In  some  cases  the  spines  are  represented 
by  granules.     On  the  anterior  and  posterior  parts  of  the  shell  the  ribs  may  be 


56  rT^ETATEOUR    LAMETJJrJTi AXCTTTA. 

smallev  tliau  clsewluTt',  but   tlie  luiddlo  rows  of  spines  are  here  often  relatively 
larger. 

Measurements  : 

(I)         (2)        (-.i)  (4)  (5)  (0)  (7)       (S)  (0-»  (10)  (in 

LeiiKtli      10      Ti      1-")      11         10     10         10     8       0-:)      Ki        -Ji  mm. 
Heiglit     21      IS     Ki     ]2-r,     11      lo:)     11      0     In         is     r2\-    „ 

(1 — 5)  li.  inncroruita  zone,  Norwich. 
(0)  „  „       Aldorluivy. 

(7)  A.  quadratus  zone,  East,  Haruham. 

(8)  B.  mucronata  zone,  Clarendon. 
(9—11)  Chalk  of  Trimingham. 

Afjhiitles. — The  form  from  the  Lower  Senonian  of  Touraine  described  and  figured 
as  Lima  r/ranulata  by  Dujardin,  is  regarded  by  Peron  '  as  belonging  to  another 
species  which  he  names  Lima  Meslei.  Peron  states  that  L.  Meslei  differs  from  L. 
granulata  in  having  more  numerous  ribs  ornamented  with  fine  granides  of  which 
the  middle  row  is  not  larger  than  the  lateral  rows  ;  further,  the  ribs  disappear  on 
the  anterior  and  postei'ior  parts  of  the  shell,  and  the  ears  are  without  ornamen- 
tation. 

liiulnla  scahrinila,  Stoliczka,"  from  the  Arrialoor  Group,  is  closely  related  to 
Lima  granulata,  but  owing  to  the  imperfect  preservation  of  the  single  valve  on 
which  the  species  is  founded,  an  exact  comparison  is  not  possible.  The  ornamen- 
tation, however,  seems  to  differ,  since  it  apparently  consists  of  small  tubercles  of 
nearly  equal  size.  It  has  been  suggested  by  Holzapfel  and  Hennig  that  Lima 
'pseuducard'uim,  Reuss,'  may  be  identical  with  L.  granulata,  but  the  ornamentation 
on  the  ribs  of  that  species  appears  to  be  unknown. 

Bemarks. — This  species  has  been  referred  to  Limea  by  Brauns,  Zittel,  and 
Griepenkerl,  l)ut  later  Avriters — Holzapfel,  Hennig,  and  RaAni — retain  it  in  the 
genus  Lima  since  they  find  no  evidence  of  the  existence  of  a  taxodont  hinge. 
The  specimens  which  I  have  seen  do  not  show  the  hinge. 

The  outline  of  the  shell  varies  to  some  extent  in  L.  granulata,  deiJcndingmainl}^ 
on  the  obliquity  of  the  valves.  The  appearance  of  the  ribs  varies  considerablj'  and 
is  probably  due  chiefly  to  the  state  of  preservation  ;  in  the  more  perfect  specimens 
the  terminations  of  the  scale-like  spines  become  erect,  in  otlici's  flic  s])ines  are 
in  llie  form  of  sloping  scales,  whilst  in  some  cases  tliey  arc  i'c|ircsciitc(l  by 
tubci'cles  onlv.      The  iuinil)er  of  ribs  also  shows  variation. 

'•  '  L'Hist.  du  Terr,  de  Craie'  (1888),  p.  148,  pi.  i,  figs.  21—24. 

2  '  Palffiont.  Indica,  Grot,.  Faima  S.  India'  (1871),  vol.  iii,  p.  419,  pi.  xxx,  fij,'.  8. 

s  'Die  Vcrstein.  der  biilim.  Krcideformat.'  (1846),  i)t.  2,  p.  33,  pi.  xxxviii,  figs.  2,  3;  Geiuitz, 
"Das  Elbthalgeb.  in  Sachsen  "  (' Paloeontograpliica,'  vol.  xx,  pt.  1,  1872),  p.  204,  pi.  xlii,  figs.  14,  1.5  : 
see  also  Braiuis  (1876),  Fritsch  (1877,  1883),  Michael  (1893),  Leonhard  (1897). 


ipaUxontoovapbical  Socict\>,  1905. 


A    MONOGEAPH 


OF    THE 


CRETACEOUS    LAMELLIBRANCHIA 


OF 


ENGLAND. 


BY 


HENRY  WOODS,  M.A. 

UNIVERSITY   LECTURER   IN    PALa:0200LOGT,  CAMBRIDOE. 


VOL.  IL     PART  11. 

Pages  57—96;  Plates  VIII— XI. 


LONDON: 

PRINTED    FOR    THE    PAL^ONTOGRAPHICAL    SOCIETY. 

1905. 


PRINTED    BY    ADLARD    AND    SON,    LONDON    AND    DORKINO. 


PTERIA.  57 

This  species  was  figured  from  the  Norwicli  Cliiilk  In-  S.  "Woodward  (1833)  as 
Plaglostoma  graniilosum,  but  apparently  he  was  unaware  that  it  had  been  previously 
described  and  figured  hj  Nilsson  under  the  similar  name  P.  gmniilatum. 
Woodward's  figure  seems  to  have  been  overlooked  by  later  writers. 

Distribution. — Actiuocamax    quadyatus    zone    of     East    Harnham,    Salisljury. . 
B,elemnite1la  iwicronnta  zone  of  Alderbury,  Clarendon  (near  Salisbury),  and  various 
localities  near  Norwich.     Chalk  of  Trimingham. 


FaHi?7?/— PTERITD.E,  Meek. 

Gemis—FTEiuA,  J.  A.  Scojjoli,  1777.' 

('  lutrod.  Hist.  Nat.,'  p.  397.) 

Sub-genus — Oxytoma,  Meel;  1864. 

('Check  List  Invert.  Foss.,  N.  America,'  jx  39;  Meek  and  Hayden,  '  Palaeout.  TJ.  Missouri,'  1864, 

Part  I,  p.  79.) 

Pteeia  (Oxytoma)  Coknueliaa'a  {iVOrbigmj),  1840.    Plate  VIII,  figs.  1,  2,  3  <i,  b,  4-7. 

1836.     AvicuLA  MACBOPTERA,  F.  A.  Bomer.    Die    Verstein.    nord-deutsch.    Oolitli.- 

geb.,  p.  86,  pi.  iv,  fig.  5  (uon  Avicula. 
macropfera,  Lamarck,  1819). 

1841.  —  —  —  Die  Versteiu.  d.  uord-deutsch.  Kreide- 

geb.,  p.  64. 

1846.  —       CoRXUELiANA,  ^.  crO)7;/(//!;/.    Pal.  Frau?.  Terr.  Crct.,  Vol.  iii,  p.  471 , 

pi.  ccclxxxix,  figs.  3,  4. 

1846.  —       PECTiNATA,  rf'OrfcjjfKy.     Ibid.,  p.  473,  pi.  cccxci,  figs.  1  — 3. 

1850.  —       CoENUELiANA,  —  Prodi'.  de  Pal.,  vol.  ii,  p.  82. 

1850.  —        PECTINATA,  —  Ibid.,  p.  82. 

?  1868.  —       CoRNUELiANA,  E.  Eickwald.     Letlijea  Kossica,  vol.  ii,  p.  508.  pi. 

xxii,  fig.  1. 
1869.  —  —  F.  J.  Pictet  a)id  G.  Caiiipiche.    Foss.  Terr.  Crct.  Ste. 

Croix  (Mater.  Pal.  Suisse,  ser.  5), 
p.  66,  pi.  dii,  figs.  1 — 4. 
1877.  —  —  G.  Buhm.    Zcitschr.  d.  deutsch.  geol.  Gesellsch.,  vol. 

xxix,  p.  237. 
"r*  1883.  —  —  W.  Keeping.     Foss.,  et*.,  Neoc.  Upware  aud  Brick- 

hill,  p.  109.  pi.  v,  fig.  2. 
1884.  —  —  0.  Weerth.     Die  Fauna  des  Neoioni.  im  Teutoburg. 

Walde  (Paheout.  Abhandl.,  vol.  ii), 
p.  50. 

1  Svn.  Avicula,  Bruguii-re,  1791. 


58  CRETACEOUS   LAMELLTBRAXCHIA. 

1889.     AvicuLA  iN.EQUiVALVis,  G.  W.  LamiiliKjh.     Quart.  Journ.Geol.  Soc.vol.  xlv, 

p.  615. 
1895.  —       CoRNUELiANA,  G.  Maag.    Zeitschr.  der  deutsch.  geol.  Gesellsch.,  vol. 

xlvii,  p.  2G7. 

1895.  —  —  F.  Vofjel.     Holliiudisch.  Kreide,  p.  55. 

1896.  —  —  A.  WoUemuini.    Zeitschr.  d.  deutsch.  j,'eol.  Gesellsch., 

vol.  xlviii,  p.  842. 

1900.  —  —  —  Die  Biv.  ii.  Gastrop.  d.  deutsch.  u. 

hoUiiud.  Neoeoms  (Ahhandl.  d.  k. 
preussisch.  geol.  Land.,  N.  P.,  pt. 
31),  p.  52. 

1901.  OxYTOMA  iN.EQuivALVE  cdf.  MACROPTERA,  L.  Waagc'ii.     .Talirli.  d.  k.-k.  geol. 

Reiohsaust.,  vol.  li,  pp.  12, 
15,  pi.  i,  figs.  7,  14,  15. 

Description. — Shell  obliquely  oval,  roundtHl.  Hoiglit  a  little  greater  than  length. 

Left  valve  moderately  convex.  Anterior  ear  triangular.  Posterior  ear  larger 
and  longer  than  the  anterior.  Surface  of  valve  with  from  12  to  21  main  rib.s  which 
are  rounded,  and  form  projections  on  the  margin  of  the  valve.  Between  the  main 
ribs  are  broad  flat  interspaces  in  the  middle  of  each  of  which  a  smaller  rib  occurs, 
and  between  these  secondary  ribs  and  the  main  ribs  one  or  more  still  smaller  ribs 
are  found.  On  the  middle  and  posterior  parts  of  the  valve  the  ribs  are  nearly 
straight,  Ijut  on  the  anterior  part  they  curve  forward.  Similar  ribs  occur  on  the 
anterior  ear;  on  the  postei'ior  ear  nuich  smaller  ribs  are  pi-esent,  and  growth 
lines  are  seen.     Fine  concentric  ridges  cross  both  i-il)s  and  interspaces. 

Right  valve  nearly  flat,  with  many  small,  sometimes  irregular  ribs,  which  may 
be  alternately  large  and  small.  Anterior  ear  ratlier  small,  witli  a  well-marked 
byssal  sinus.     Posterior  ear  large,  pointed,  with  small  radial  riljs. 

Medsurements : 


(1) 

(2) 

(3) 

Length 

26 

24 

]  o  mm 

Height 

27 

25 

15     „ 

(1,  2)  Speeton  Clay  (D  1),  Speetou. 
(3)  Claxhy  Ironstone,  Claxby. 

Affinities. — P.  {O.rijtoma)  CurniwUdiin  is  distiuguisheil  from  tlie  other  Cretaceous 
species  of  Oj'ijtoina  l)y  the  broad  interspaces  on  which  several  smaller  ribs  occur. 
It  belongs  to  the  persistent  and  variable  series  of  forms,  ranging  from  the  Rh;etic 
to  the  Chalk,  of  which  Ptcria  iniequifulvis  (Sowerby)  is  the  type,  and  it  is  regarded 
by  L.  Waagen  as  only  a  variety  of  that  species. 

In  most  of  the  English  specimens  the  main  ribs  are  more  numerous  but  less 
prominent  than  in  the  examples  figured  by  d'Orl)igny  and  by  I'ictet  and  Campiche. 


PTERIA.  59 

But  the  niiinl)ei'  of  those  ribs  A-aries  considerably,  and  our  specimens  agree  per- 
fectly with  the  figures  given  by  Waagen.  The  specimens  from  Faringdon  are 
smaller  than  those  found  in  the  Speeton  Clay,  and  they  present  some  resemblance 
to  P.  pediiuda  (see  beloAv),  Ijut  the  presence  of  several  smaller  ribs  in  the  inter- 
spaces connects  them  with   /'.  Corniieliana. 

Types. — From  the  Hils-thon  of  Elligser  Brink.  The  specimen  from  Upwarc 
figured  hy  Keeping  is  in  the  Sedgwick  ]\Iuseuni  ;  it  is  imperfectly  preserved,  but  is 
probably  an  example  of  this  species. 

Dlstrihidion. — Speeton  Clay  (zone  of  Bclemnites  lateralis,  D 1)  of  Speeton. 
Claxby  Ironstone  (zone  of  B.  hifcralis)  of  Claxby.  Tealby  Clay  (zone  of  B.jacnlum) 
of  Claxby.     Lower  Greensand  of  Faringdon.     Gault  of  Folkestone.' 


Pteeia  (Oxytoma)  fectinata  (Snirrrbi/),  1830.     Plate  VIII,  figs.  8a, I>,  0,  10,,,/,, 

11-1:3,  Ua,  h. 

1836.     AvicuLA  PECTiNATA,  J.  de  C.  Soirerby.     Tiuns.  Geol.  Soc,  ser.  2,  vol.  iv,  iip. 

128,  338,  pi.  xiv.  fig.  3. 
1854.  —  —  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  163. 

1869.  —  —  F.J.  Pidet  and  G.  Campiche.     Foss.  Terr.  Crct.  Ste. 

Croix  (Mati'r.  Pal.  Suisse,  ser.  5), 

p.  70. 

Nou  1846.  —  —A.  d'Orhljinj.     Pal.  Fraiu'.  Terr.  Crut.,  vol.  iii,  p.  473, 

pi.  cccxci,  figs.  1 — 3. 

s 

JJcscii'iiiidn. — Shell  small,  obli(jueIy  oval,  with  evenly  rouiuled  margin.  Height 
a  little  greater  than  length. 

Left  valve  convex,  ornamented  with  luimerous  slender  ribs  often  having  sharp 
sunnnits.  Frequently  the  ribs  are  of  two  sizes — larger  and  smaller,  alternating  in 
a  more  or  less  regular  manner.  But  in  some  cases  the  ribs  near  the  margin  of  the 
valve  are  of  equal  or  nearly  equal  size.  The  interspaces  are  flattened  and  con- 
siderably broader  than  the  ribs.  Anterior  ear  moderatel}'  large,  triangular,  the 
outer  angle  nearly-  a  right  angle ;  surface  with  ribs  similar  to  those  on  the  rest  of 
the  valve.  Posterior  ear  much  longer  than  the  anterior,  wing-like,  with  concave 
growth-lines;  on  the  dorsal  part  a  few  slender  ribs  occur  but  are  often  indistinct 
or  absent  near  the  valve. 

Right  valve  moderately  convex  dorsally,  flattened  ventrally,  surface  smooth  or 
wdth  very  fine  radial  and  concentric  ribs.  Posterior  ear  large,  not  distinctly  limited. 
Anterior  ear  small. 

'  The  only  specimen  seen  from  this  horizon  is  in  the  British  Museum,  No.  L.  16,880. 


60 


CRETACEOUS   LAMELLTBRAXCHIA. 


leasure meats  : 

(1) 

(2) 

(3) 

(4) 

(5) 

Length 

16 

10 

9-5      . 

<) 

8  mm 

Height' 

17 

12 

10 

11 

9     „ 

(1)  Hythe  Beds  (Bari^'atc  Stone),  St.  Katherine's  Chapel,  Guildford. 
(2 — 5)  Folkestone  Beds,  Folkestone. 

Affinities. — The  shell  in  tliis  species  is  smaller  than  in  /'.  ('iiiiiiicVunia  (see 
above) ;  also  the  main  ribs  on  the  left  valve  are  closer  together,  more  numerous, 
and  between  them  not  more  than  one  small  ril)  is  found.  The  ornamentation  on 
the  right  valve  is  very  much  finer  than  in  i'.  CornueUana.  See  also  rteria 
[OxijtovM)  tenuicustata  (below). 

Type. — The  type  came  from  the  Folkestone  Beds  of  Risborough,  but  appears  to 
have  been  lost.  Another  specimen,  however,  from  the  same  locality  is  in  the 
Fitton  Collection  in  the  Museum  of  the  Geological  Society. 

Distribiifioii. — Hythe  Beds  (Bargate  Stone)  of  St.  Katherine's  Chapel,  Guild- 
ford. Sandgate  Beds  of  Parham.  Folkestone  Beds  of  Folkestone.  Recorded  by 
Topley  from  the  Hythe  Beds  of  Hythe.  Gault  of  Folkestone  (British  Museum, 
No.  L,  492G).^  Upper  Greensand  of  Ventnor,  and  Crook  Hill,  Cheddington 
(Dorset). 


Pteria  (Oxytoma)  sp.     Plate  VIII,  fig.  \')((,  h. 

Some  very  small  examples  of  a  Pterin  similar  to  P.  pectiutita  are  found  in  the 
Totternhoe  Stone  of  Hitchin.  They  are  not  well  preserved,  but  appear  to  be  dis- 
tinguished from  P.  pectinata  by  the  presence  of  transverse  ribs  placed  at  regular 
distances  in  the  spaces  between  the  radial  ribs. 


Pteria  (Oxytoma)  uubia  {Etheri,l<jr),  1S81.     Plate  VIII,  fig.  16  a,  h. 

1881.     AvicuLA  DUBiA,  R.  Efhi'rid(je.     In  Penning  and  Jiikes-Bro-\viie.  Greol.  Cam- 
bridge, p.  145,  pi.  ii,  figs.  4,  4  IT. 

Remarlcs. — lliis  is  known  only  by  the  tu'o  type  specimens — one  being  a  right 
valve  separated  from  the  matrix,  the  other  a  left  showing  the  interior  onl}-.  The 
surface  of  the  right  valve  is  smooth.     Since  the  exterior  of  the  left  valve  is  mi- 

^  Measured  obliquely  to  the  hinge-line. 

*  The  species  recorded  from  the  Gault  of  Folkestone  as  Avicula  liaiili)nana.  d'Orbiguy  (see  Jukes- 
Browne,  '  Cretaceous  Rocks  of  Britain,'  vol.  i,  p.  4(55),  is  probably  Pteria  ^lectiiuita. 


PTERIA.  Gl 

known,  the  characters  and  affinities  of  this  "  species  "  cannot  be  determined.     The 
left  valve  has  a  length  of  (3  mm. 

Types. — In  the  Sedgwick  Museum,  (Cambridge. 

Disfribidiou. — Totternhoe  Stone  (zone  of  Rolisler  siibijlobjsiu)  of  Burwell.' 


Pteria    (Oxytoma)    tenuicostata  (Burner),  1841.      Plate   VIII,    figs.    17  a-d,    18, 

li)a,b,  20a,  h,  21  a,  6,  22,  23. 

1841.     AviCTjLA  LiNEATA,  F.  A.  Burner.     Die  Versteiu.  d.  uord-deutsch.  Kreidegeb., 

p.  64,  jil.  viii,  fig.  15  {A.  tenuicostata  on 
pi.  viii). 
1850.  —       SUBLINEATA,  ^.  f/'O/'fti'i/Hy.     Pi'odr.  dc  Pal.,  vol.  ii ,  p.  249. 

1869.  —       TENUicosTA,  F.  J.  Pidet  and  G.  Campiche.    Foss.  Terr.  Crit.  Ste. 

Croix  (Matei-.  Pal.  Suisse,  ser.  5), 
p.  73. 
1878.  —       TENUICOSTATA,  /.  F.  Blake.     Proc.  Geol.  Assoc.,  vol.  v,  p.  259. 

1882.  —  —  n.  ScJiriider.     Zeitsclii-.  d.  deutscli.  geol.  Gesellsch., 

vol.  xxxiv,  p.  271. 
1888.  —  —A.  Peron.     L'Hist.  du  Terr,  de  Craie,  p.  153,  pi.  i, 

figs.  11,  12. 
1904.  —  —  A.W.  Roive.     Proc.  Geol.  Assoc,  vol.  xviii,  p.  266. 

Non  1845.  —  —  A.  d'Orbigny,  in  Murchi8on,deVerneuil,  and  Keyser- 

litiy.     Gl'oI.  de  la  Eussie  d'Europe, 
vol.  ii,  p.  490,  pi.  xliii,  figs.  5 — 7. 
—    1854.  —        LiMEATA,  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  163. 

Bescriptlon. — Shell  oliliijuelv  oval,  usually  longer  than  high. 

Left  valve  moderately  convex ;  with  evenly  convex  margins,  except  the  postero- 
dorsal,  which  is  slightly  concave.  Ears  large,  the  anterior  indistinctly  limited,  and 
with  its  outer  angle  rectangular  or  slightly  obtuse.  Posterior  ear  longer  and  more 
distinctly  limited  than  the  anterior,  with  the  dorsal  portion  extended  and  wing- 
like. 

Ornamentation  of  left  valve  consists  of  numerous  (sometimes  as  many  as  100) 
narrow,  well-mai-ked,  evenly  rounded  ribs  separated  by  broad,  flat  interspaces. 
The  anterior  ribs  are  slightly  less  prominent  than  the  others ;  those  near  the  jdos- 
terior  border  are  often  closer  together.    At  the  margin  of  the  valve  the  ribs  usually 

1  Another  specimen  fnun  the  same  locality  and  ]iorizt>u  was  described  by  Etheridge  as  jlwcit/a 
filaia  (Penning  and  Jukes-Browne,  'Geol.  Camb.,'  p.  14t,  pi.  ii,  fig.  3).  I  am  unable  to  accept  the 
generic  position  assigned  to  this  species  by  Etheridge;  it  may  be  an  Ostrea,  but  appears  to  be  closely 
allied  to  the  shell  described  as  Anomia  subradiata  by  Eeuss  ('  Die  Versteiu.  der  bohm.  Kreideformat.,* 
pt.  2,  1846,  p.  45,  pi.  xxxi,  figs.  18,  19).  The  type  and  three  other  specimens  of  Acicu'.a  filaia  are  iu 
the  Sedgwick  Museiun,  Cambridge. 


62  CRETACEOUS   LAMELLIBRANCHIA. 

show  a  more  or  less  regular  alternation  in  size,  l)ut  sometimes  two  or  three  of  the 
larger  ribs  occur  in  proximity  without  the  intervention  of  smaller  ribs.  In  some 
cases  between  the  large  and  small  riljs  a  rib  of  still  smaller  size  is  found.  Some  of 
the  large  ribs  start  from  near  the  umbo ;  others  start  at  some  little  distance  from 
it  but  soon  reach  the  same  size  as  the  primary  ribs ;  still  other  ribs  are  intercalated 
at  a  greater  distance  from  the  umbo  and  do  not  attain  the  same  size  as  the 
earlier  ribs.  The  anterior  and  posterior  ribs  have  a  slight  curvature ;  the  others 
are  more  nearly  straight.  Occasionally  the  anterior  and  posterior  ribs  have  a 
faintly  marked  nodose  appearance.  The  interspaces  are  smooth,  or  have  a  very 
faintly  marked  radial  ribbing.  'J'he  anterior  ear  is  ornamented  with  ribs  similar  to 
those  on  the  remainder  of  the  valve,  bvit  they  are  of  uniform  or  nearly  uniform 
size.  The  posterior  ear  is  marked  with  growth-lines  parallel  to  its  posterior  con- 
cave border  ;  radial  ribs  also  occur,  and  are  rather  larger  and  more  widely  separated 
on  the  dorsal  portion  than  on  the  part  near  the  junction  with  the  rest  of  the  valve. 

Right  valve  much  smaller  than  the  left ;  flattened,  liut  convex  in  the  median 
dorsal  part.  Anterior  ear  with  a  deep  sinus.  Posterior  ear  much  larger,  but  not 
marked  off  from  the  rest  of  the  valve.  Surface  smooth,  or  with  vei-y  faint  concen- 
tric lines. 

Mcas-urements  of  left  valves  : 

(1)  (2) 

Length         .         27         26 

Height  (oblique)  25-5      23 

(1,  8)  A.  cpiadriifii.<  zc>ne,  West  Haruluiiu. 
(2,  5)  „  ,,      Coddenhaiii. 

(4)  Upper  Chalk,  Euston  Parva. 

(3,  6,  7)  „  Wells. 

Affinities. — Pteria  danica  (Ravn) '  is  similar  in  outline  and  the  general 
character  of  its  ornamentation  to  Pteria  tenuicostata,  but  appears  to  be  dis- 
tinguished by  the  possession  of  fewer  ribs  and  by  their  aljsence  in  the  neighbour- 
hood of  the  umbo. 

In  the  character  of  its  ornamentation  P.  tennicostata  closely  resembles  P. 
pectinata  (see  p.  59),  but  is  distinguished  by  its  larger  size,  relatively  greater 
length,  and  smaller  convexity ;  also  the  ribs  are  more  numerous,  the  ears  are 
relatively  larger,  and  the  anterior  left  ear  is  less  distinctly  limited. 

The  specimen  from  Simbirsk  figured  by  d'Orbigny  (1845)  as  Avicula  tenm- 
costatd  differs  from  that  species  in  the  possession  of  fewer  and  stronger  ribs.  It 
was  subsequently  regarded  by  d'Orbigny-  as  an  example  of  Avicula  laripes,  Morton.^ 

'  'Mollusk.  i.  Daiimarks  Kri.ltaflej,'  i.  (1902),  p.  70,  pi.  i,  figs.  1,  2. 

"  'Prodr.  de  Pal.,'  vol.  ii  (1850),  p.  2i9. 

*  '  Synopsis  Org.  Remains  Cret.,  U.S.'  (1834),  p.  63,  pi.  xvii,  fig.  5. 


(3) 

(4) 

(5) 

«!) 

(V) 

(8) 

26 

20-5 

19 

19 

l;3-5 

12    mm. 

22 

19 

18 

17 

U-75 

11-25  „ 

PTERTA.  03 

Bemarlcx. — In  England  this  species  has,  up  to  the  present  time,  been  definitely 
recognised  in  the  Adlnocamux,  qnadratus  zone  only. 

The  specimen  figured  by  Romer  is  relatively  higher  than  most  of  tlie  EiigHsh 
examples,  but  in  other  characters  tliere  is  close  agreement. 

Pferia  scminuda  (Dames) '  resembles  Pteria  tennicostatd,  l)ut  appears  to  differ 
in  the  ribs  on  the  left  valve  being  of  more  nearly  uniform  size,  and  in  tlie  presence 
of  distinct  ornamentation  on  the  right  valve. 

Type. — The  type  is  stated  by  Romer  to  have  come  from  the  Lower  Chalk  of 
Lindner  Berg,  near  Hanover,  but  according  to  Dr.  J.  Bohm  the  horizon  is  really 
the  quadratns  Chalk. 

Distribution. — Zone  of  Jdinocamax  quadrntn.-i  of  West  Harnham,  near  Salisbury, 
and  Sewerby  (Yorkshire).  Upper  Chalk  (?  A.  quadratics  zone)  of  Coddenham 
(Suffolk),  Wells  (Norfolk),  and  Ruston  Parva  (Yorkshire). 


Sub-ijcints — PsEUDOPTER.\,  F.  B.  Meel;  1873. 

('  6tli  Ann.  Eep.  U.S.  Geol.  Survey  of  the  Territories,'  p.  489;  Meek,  '  Invert.  Cret.  and  Tert.  Poss. 
U.  Missouri '  (Eep.  U.S.  Geol.  Survey,  vol.  ix,  1876),  p.  29.) 


PtEBIA   (PSEUD0PTER.\.)    SUBDEPRESSA    {d'Orhijilij),    1350.       Plate   IX,  fig.    hi,    b. 

1845.     AvicuLA  DEPEESSA,  E.  Forbes.     Quart.  Journ.  Geol.  Soo.,  vol.  i,  p.  247,  pi.  iii, 

fig.  7  (uou  A.  depressa,  Miinster,  1841). 
1850.  —       SUBDEPBESSA,  A.  (VOrhujny.     Prodr.  de  Pal.,  vol.  ii,  p.  119. 

1854.  —        DEPRESSA,  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  163. 

1855.  —        suBDEPEESSA,  G.  Cotteau.     MoU.  Foss.  de  I'Yonne,  p.  104. 

1869.  —  —  F.J.  Pidet  and  G.  Campiche.     Foss.  Terr.  Crct.  Ste. 

Croix  (Mati'r.  Pal.  Suisse,  ser.  5), 
p.  70. 
1871.  —  —  F.  Stoliczka.     Palseont.  ludica,  Cret.  Fauna  S.  ludia, 

vol.  iii,  p.  398. 
Remarks. — This  species  is  very  imperfectly  known  at  present.     It  resembles 
P.  Jialdonensis  from  the  L^pper  Greensand  of  Haldon  (see  below)  but  is  easily  dis- 
tinguished by  the  strong  concentric  ridges ;  it  also  appears  to  be  relatively  louger 
and  less  convex. 

Type. — In  the  Museum  of  the  Geological  Society  (No.  2050). 
Distnbutiou. — Lower  Greensand  (Crackers)  of  Atherfield.     Recorded  by  Topley 
from  the  Atherfield  Clay  of  Peasmarsh  and  Shalford. 

'  •  Zeitschr.  d.  deutseh.  geol.  Gesellseh.,'  vol.  xxvi  (1874),  p.  765,  pi.  xxi,  fig.  3  ;  Notling,  '  Die  Fauua 
d.  baltisch.  Ccuomau.'  (Palseout.  Abliaudl.,  vol.  ii,  1885),  p.  21,  pi.  iii,  figs.  7,  8. 


?  1846. 

— 

?  1842. 

Gervillia 

?  1845-6. 

AVICULA 

?  1850. 

— 

1854. 



1868. 

— 

64  CRETACEOUS   LAMELLIBRANCHIA. 


Pteeia  (Pskudopteea)  anomala  {Soicerlnj),  183G,    Plate  IX,  figs.  2a-d,  3rt,  h,  40,1. 

1836.     AvicuLA  ANOMALA,  /.  de  C.  Suwerhy.     Traus.  Geol.  Soc,  ser.  2,  vol.  iv,  pp. 

240,  342,  pi.  xvii,  fig.  18. 

—  A.  E.  Beiiss.     Die  Yerstein.  der  liiilim.  Kreiilefunnat., 
pt.  2,  p.  22,  pi.  xxxii,  figs.  1 — 3. 

—  H.  B.  Geinitz.     Cliar.  d.  Seliielit.  u.  Petref.  des  siichs. 
Kreidegeb.,  pt.  3,  p.  80,  pi.  xx,  fig.  38. 

—  —  Griindriss  d.  Verstein.,  p.  459,  pi.  xx, 
fig.  5. 

—  —  Das  Quadersandst.  oder  Kreidegeb.  iu 
Deutsclilaud,  p.  170  {partim). 

—  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  163. 

—  A.  Briart  and  F.  L.  Cornet.     Descript.  Mineralog.  Gi'ol. 

et  Pal.  de  la  Meule  de  Bracquegnies  (Mem. 
cour.  et  MJm.  des  Sav.  ctraugers,  vol.  xxxiv), 
p.  52,  pi.  iv,  fig.  7. 
1869.  —  —        F.  J.  Pictet  and  G.  Campiche.     Foss.  Terr.  Crct.  Ste. 

Croix  (Mater.  Pal.  Suisse,  ser. 
5).  p.  71. 
1871.  —  —        F.   iSfolicxka.     Palseout.  Indica,  Cret.  Fauna   S.  ludia, 

vol.  iii,  p.  398. 
?  1873.  —  —        H.  B.  Gelnitz.     Das  Elbthalgeb.  in  SacLseu  (Pateouto- 

grapliica,  vol.  xx,  pt.  1),  p.  207,  pi. 
xlvi,  figs.  5,  6. 
lyyij.  —  —        Ji,  Michael.     Zeitsehr.  der  deutsch.  geol.  Gesellseh.,  vol. 

xlv,  p.  233. 

Nou  1846.  —  —        A.  d'Orhiijnij.     Pal.  Franc.  Terr.  Cri't.,  vol.  iii,  p.  478,  pi. 

cccxcii,  figs.  1 — 3. 

—  1850.  —  —        d'Orhigny.     Prodr.  de  Pal.,  vol,  ii,  p.  167. 

?  —    1877.  —  —        A.  Fritseh.    Stud,  ini  Gebiete  der  bdhm.  Kreidefoniiat. : 

II,  Weisseuberg.  u.  Malnitz.  Scliieht.,  p. 
128,  fig.  108. 

—  1883.  _  _  _  Ibid.,  Ill,  Iserschicht.,  p.  109. 

Description. — Shell  rather  large;  outline  (without  the  ears)  triangular,  very 
oblique  ;  anterior  margin  convex,  forming  a  rounded  angle  with  the  sinuous  postero- 
ventral  margin.  Umbo  of  left  valve  pointed,  acnte,  near  the  anterior  extremity. 
Apical  angle  about  45°. 

Left  valve  very  convex,  with  a  strong,  rounded  ridge  extending  from  the 
umbo  to  the  postero-ventral  extremity.  In  front  of  this  ridge  the  shell  curves 
rapidly  downAvards,  and  becomes  nearly  vertical  to  the  plane  of  the  valves  near 
the  anterior  margin  and  near  the  anterior  ear.  Behind  the  ridge  the  valve  is 
flattened  and  slopes  dorsally  (fig.  2  o) ;  l)ut  this  part  is  sometimes  divided  into  two 


PTERTA.  65 

by  a  median  step-like  fold  (fi,n-.  '^  (i).  A  iian'ow  ])art  adjoining  the  posterior  ear 
slopes  rather  rapidly. 

Anterior  ear  of  moderate  size,  convex,  much  higher  than  lung.  Posterior  ear 
large,  united  to  the  whole  of  the  postero-dorsal  margin  of  the  valve ;  posterior 
margin  of  ear  slightly  concave  or  sinuous,  forming  an  obtuse  angle  with  the  hinge- 
line  and  also  with  tlie  postero-ventral  margin. 

Ornamentation  consists  of  numerous  radial  ril)s  whieli  are  straight  or  slightly 
nndidating,  and  extend  over  the  larger  part  of  the  valve.  On  the  posterior  ear  the 
ribs  are  narrow  and  separated  by  broad,  flat  or  slightly  concave  interspaces.  On 
the  flattened  part  of  the  valve  the  ribs  are  rather  more  rounded  and  become  less 
distinct  towards  the  postero-ventral  margin  in  large  specimens.  In  front  of  the 
main  ridge  the  ribs  are  closer  together  and  the  interspaces  very  nari'ow  ;  on  the 
anterior  part  of  the  valve  and  on  the  anterior  ear,  ribs  are  either  absent  oi- 
indistinct.  Numerous,  close-set,  regular,  concentric  linear  ridges  cross  both  ribs 
and  interspaces. 

In  small  specimens  (figs.  4ii,  h)  having  the  ornamentation  well  preserved,  the 
ribs  on  the  flattened  part  of  the  valve  are  naiTOw,  rounded,  distinctly  limited, 
and  separated  by  I)road  interspaces;  new  ribs  are  introduced  in  the  middle  of 
some  of  the  interspaces.  The  ribs  and  interspaces  are  crossed  at  regular  intervals 
by  concentric  ridges  which  form  squares  or  oblongs  with  the  ribs.  On  the  posterior 
ear  similar  ornamentation  occurs,  )iut  the  concentric  ridges  cut  the  ribs  obliquely. 

Right  valve  not  seen. 

MeasurcinriitK  : 

(1)  (2) 

ITml)0  to  postero-ventral  extremity         80         .  .  75  mm.  * 

Length  of  hinge-line        ...         49         .  .  54     ,, 

(1,  2)  Blackdowu. 

Affinities. — The  specimen  from  the  Cenonianian  of  Le  Ahms  figured  l)y 
d'Orbigny  as  Arinihi  anoviuda  appears  to  be  distinct  from  Sowerby's  species  on 
account  of  its  larger  apical  angle  and  its  fewer,  stronger,  and  moi-e  spiny  ribs.  See 
also  1\  {Pi^endoptpm)  haldovensis  (below). 

The  character  of  the  hinge  in  this  and  the  other  species  here  included  in  the 
sub-genus  I'seudoptera  is  unknown  ;  consequently  their  systematic  position  cannot 
be  regarded  as  definitely  determined. 

BpiiKirh.^The  oidy  examples  Avhich  1  have  seen  are  the  type  specimen,  six 
specimens  in  the  British  Museum,  and  two  in  the  Museum  of  Practical  Geology. 
Those  from  Haldon  have  the  ornamentation  very  perfectly  preserved. 

Ti/pe. — In  the  Bristol  IMuseuui,  from  Blackdown. 

Disfnbntiuii. — Upper  Greensand  (zone  of  ScJda'ubachia  rostrata)  of  Blackdown 

and  Haldon. 

9 


66  CRETACEOUS   LAMELLIBRANCHIA. 

Ptehia  (Pseudoptkka)  iiAi.iioNENSis,  sp.  iiov.     Plate  IX,  figs.  5,  Cxiji,  7,  8  a-c,  0,  10. 

Description. — Shell  of  moderate  size,  triaiigulai-,  very  oblique.  Anterior  margin 
slightly  convex,  forming  a  rounded  angle  witli  the  postero-ventral  margin.  Umbo 
pointed,  acute,  near  the  anterior  extremity.     Apical  angle  about  43°. 

Left  valve  very  convex,  with  a  sharp  carina  extending  from  the  innbo  to  the 
postero-ventral  angle.  The  part  of  the  valve  in  front  of  the  carina  is  bent 
sharply  downwards  along  its  whole  length,  and  is  ornamented  witli  from  ten 
to  eighteen  slender,  linear  ribs,  which  are  separated  by  l)road  flat  interspaces. 
The  number  of  rilis  increases  with  age  (nving  to  the  intercalation  of  new  ribs 
in  the  interspaces.  The  space  between  the  carina  and  the  first  rib,  and 
sometimes  also  between  the  first  and  second  lib,  is  greater  than  the  space 
between  the  ribs  near  the  middle  of  the  anterior  part  of  the  valve.  jVIinute 
spiny  projections  are  present  on  the  riljs  in  well-preserved  specimens.  A  similar 
but  rather  stronger  rili,  also  with  spiny  projections,  occurs  on  the  carina. 
Behind  the  carina  two  short  ribs,  extending  from  near  the  middle  to  the  margin  of 
the  valve,  are  sometimes  seen.  The  larger  part  of  the  valve  l)eliind  the  carina  is 
flattened  and  smooth  except  for  numerous,  slightly  curving  growth-ridges,  which 
are  continued  on  to  the  posterior  ear,  and  are  sometimes  seen  in  front  of  the  carina, 
where  they  may  Ijecome  more  prominent. 

Anterior  ear  small,  with  rounded  margin,  indistinctly  separated  from  the 
remainder  of  the  valve,  ornamented  with  radial  ribs  similar  to  those  on  the 
adjoining  part  of  the  valve. 

Posterior  ear  compressed,  very  large,  separated  from  the  remaiudei-  of  the 
valve  by  a  very  shallow  depression.  Growth-ridges  concave  and  parallel  with 
the  posterior  margin. 

Right  valve  not  seen. 

Measuremcntti : 


(1) 

(-') 

(3) 

(■*) 

(5) 

Height  (oblique)     .     28     , 

,     20 

.     25     , 

.     23     , 

18  mm. 

Length  of  hinge-line^  19 

,     ir, 

.     18 

.     15     , 

12 

(1 — 5)  Upper  Greensand,  Hakloii. 

Affinities. — This  species  is  closely  allied  to  Pferia  (PsemJoptera)  raricosta  (Reuss),* 
from  the  Gosau  Beds  of  St.  Wolfgang  (Salzburg),  but  is  distinguished  by  the 
smaller  obliquity  of  the  shell,  l)y  the  angle  formed  by  the  anterior  and  postero- 

'  This  measurement  is  approximate  only,  since  the  posterior  wing  is  usually  imperfectly  presei-ved. 

-  Reuss,  'Char.  d.  Kreideschicht.  iu  den  Ostalpeu,'  etc.  (Denkschr.  d.  k.  Akad.  Wisseusch.  Wien, 
Math.-nat.  CI.,  vol.  vii,  1854),  p.  147,  pi.  xxviii,  tig.  16;  K.  A.  Zittel,  'Die  Bivalven  d.  Gosaugeb.' 
(Ibid.,  vol.  XXV,  pt.  ii,  186(3),  p.  90,  pi.  xiii,  fig.  6;  .4.  (jlahra,  Geinitz,  'Das  Elbthalgeb.  iu  Sachsen ' 
(Palseontographica,  vol.  xx,  pt.  i,  1873),  p.  208,  jil.  xlvi,  fig.  7,  and  pt.  ii,  pi.  xi,  fig.  2  ?  ;  Niitling,  '  Die 
Fauna  d.  baltisch.  Cenoman.'  (Palieont.  Abhaiidl.,  vol.  ii,  1885),  p.  22,  pi.  iii,  fig.  9. 


PTERIA.  Q7 

ventral  margins  being  smaller,  iind  by  tlie  shorter  postero-ventral  margin.  Tt  also 
resembles  P.  {Psen(h>/ifi;-<i)  ir/nabenfeims  (Lundgren),'  from  the  Senonian  of 
Ignaberga. 

P.  {P-^cviJdjifrra)  liiihlnitcHftix  is  distinguisla'd  from  the  young  of  1'.  {J'spiiiloptniv) 
anovKihi  (see  aboA'e)  liy  its  sharp  carina;  by  the  part  of  the  valve  behind  the  carina, 
and  the  posterior  Aving,  l)eing  smooth;  also  l)y  the  strong  and  more  widely  sepa- 
rated ribs  in  front  of  the  carina. 

Types. — In  the  British  Museum  and  the  Sedgwick  Museum. 

DistrihvHov. — Upper  Greensand  (zone  of  T'erfen  asprr)  of  Haldon. 

Pteeia  (Psei'dopteiia)  OAUETixA,  sp.  iiov.     Plate  IX,  figs.  1 1  n,  I,,  1-2  ii,h. 

Description. — Shell  small,  very  oblique.  Umbo  acute,  near  the  anterior 
extremity.     Apical  angle  2(5°  to  :^2°. 

Left  valve  moderately-  convex,  Avith  the  median  triangular  part  raiseil  but 
flattened  ;  in  front  of  this  the  valve  bends  sharply  to  the  anterior  margin  ;  l)ehind, 
it  bends  rather  sharply  to  join  the  posterior  ear,  which  is  distinctly  demarcated. 
Anterior  ear  small.  Posterior  ear  moderately  large,  united  to  the  greater  part  of 
the  postero-dorsal  margin  of  the  valve ;  its  posterior  margin  concave. 

A  few  narrow,  well-defined  radial  ribs  occur  on  the  anterior  part  of  the  raised 
triangular  portion  and  just  in  front  of  it.  In  some  cases  less  distinct  ribs  with 
spiny  pi'ojections  are  present  on  the  whole  of  the  triangular  part  of  the  valve. 
Growth-ridges  are  often  well-marked,  and  are  continued  on  to  the  posterior  ear. 

Measurements  ; 

Hinge-line      .  .  .  .  .11  unii. 

Height  (oblique)  .  .  .  .     21      ,, 

Black  Veil. 

Affinities. — This  species  is  distinguished  from  I'tcria  {Fscv(hi2)tt'T(()  haldonensis 
(see  above)  by  (1)  the  greater  obliquity  of  the  shell,  (2)  the  smaller  apical  angle, 
(3)  the  absence  of  the  sharp  carina,  (4)  the  distinctly'  limited  posterior  ear. 

Ti/pes. — In  the  Museum  of  Practical  Geology  (No.   10,780)  and  the   Sedgwick 
Museum. 

histrilmtimi. — Gault  of  Black  Vt-n. 

Ptekia  (PskuikiI'tei.'a)  (■(i:ia'i.i:sc'p:xs  (Nilsson),  1827.     Plate  IX,  figs.  13-10,  17",/', 
18,  19a,l>. 

1827.     AvicuLA  cffiEULESCENS,  S.  NUsson.     Petrif.  Suecana,  p.  18,  pi.  iii,  fig.  19. 
?  1836.  —  A.  Gold/iisg.     Petref .  Germ.,  vol.  ii,  p.  132,  pi.  cxviii, 

fia.  6. 


» '  Mollusk.  i  MammiMus  och  Mmronata  Zonerna  i  Nordijstra  SkSne '  (1894),  p.  44,  pi.  i,  tig.  2. 


68  CRETACEOUS    LAMELLTBRAXCHIA. 

?  1841.     AvicuLA  ccERULESCENs,  F.  A.  Bottler.    Die  Verstein.  d.  iiurd-deutsch.  Kreide- 

geb.,  p.  64. 
1850.  —  —A.  (VOrhiyii!/.     Prodr.  .le  Pal,  vol.  ii,  p.  249. 

1888.  —        cjenvLESCEms  A.  Pi'i-iin.    Hist.  Terr,  de  Craie,  p.  155,  pi.  i,  fig.  14. 

?  1889.  —       cffiKXJLESCENs  E.  Holzap/il.     Dip  Mollusk.  Aachen.  Kreide  (Palae- 

oiitographica,  vol.  xxxv),  p.  227. 
1897.  —  —  A.   Heiuiig.      Kevis.   Lamell.    i   Nilssou's   'Petrif. 

Siieeana,'  p.  54,  pi.  iii,  figs.  25 — 27. 

Descripfloii. — Shell  rather  small,  ol)lii|ue,  triangular.  Anterior  margin  slightly 
convex  oi'  nearly  straight.  Umbo  rather  near  the  anterior  e.xtreinity,  sometimes 
curved  slightly  backwards.  Anterior  ear  small,  not  distinctly  marked  off  from  the 
rest  of  the  valve.  Posterior  ear  large,  triangular,  its  inner  margin  not  limited,  its 
posterior  margin  slightly  concave  and  continuous  with  tlie  postero- ventral  margin 
of  the  valve.  Median  part  of  the  valve  raised,  extending  obliquely  backwards,  some- 
times subcarinate  anteriorly.  In  front  of  this  raised  part  the  valve  is  bent  more  or 
less  sharply;  behind,  it  is  compressed  gradually.  Surface  with  weak  radial  ribs,  which 
are  straight  or  slightly  undulating,  and  bear  small  spiny  or  scaly  projections  some- 
times close  together,  sometimes  more  or  less  widely  separated.  The  ribs  may 
occur  on  the  anterior  part  only,  or  may  be  present  over  the  entire  shell,  including 
the  ears.  Often  on  the  anterior  part  they  are  closer  together  than  elsewhere.  The 
number  of  ribs  and  the  width  of  the  flat  interspaces  vary  in  different  specimens. 
New  ribs  may  be  introduced  in  the  interspaces  at  varying  distances  from  tlie  umbo. 
In  some  specimens  numerous  fine  concentric  lines  are  seen. 

Medsaremeuts  : 

(1)  (2)  (3) 

Length      .         .  11  .         11  ,  10     nnii. 

Height      .         .         13         .         12         .         lO-.-)     „ 

(1)  A.  qiiadratus  zone.  East  Hariibain. 

(2)  B.  miicronata  zone,  Norwich. 

(3)  „  „     Clarendon. 

Apiiiifics. — The  imperfect  specimen  from  the  Lower  Senoniau  of  Brunswick 
figured  by  (i.  Midler'  as  Avlcnla  sp.  may  perhaps  be  an  example  of  P.  rirntlescens. 

Avicnla  'jlahru,  Reuss,"  resembles  in  t'niui  /'.  c(Cridesceus,  but  is  distinguished 
by  the  absence  of  radial  ril)s. 

Avicnla  subnodosa,  Hagenow,''  from  tlio  Senonian  of  Riigen,  is  pcrliaps  iden- 
tical with  P.  cmrulescens,  but  in  tlic  absence  of  a  figure  of  tlie  former  1  am  unable 
to  make  a  comparison. 

'  '  Mollusk.  d.  Uuterscn.  v.  Brauusclnvoig  u.  Ilsedy '  (ls;»8),  p.  oi*,  pi.  v,  fig.  10. 
2  '  Die  Verstein.  der  bohm.  Kreidefonnat.'  (1846),  pt.  2,  p.  22,  pi.  xx.\ii,  figs.  4,  5. 
■■*  'Neues  Jahrl),  fiir  Min.,'  etc.  (1842),  p.  559. 


AUCELLA.  69 

Remarl-s. — The  English  specimens  have  the  median  part  of  the  valve  apparently- 
less  sharply  marked  off  from  the  anterior  and  posterior  parts  than  it  is  in  the 
examples  figured  by  Hennig,  but  they  agree  in  this  respect  with  the  figure  given 
by  Peron. 

The  specimens  show  some  variation  in  obliquity  and  in  their  relative  height 
and  length.  The  differences  seen  in  the  ornamentation  are  probably  due,  in  part, 
at  any  rate,  to  imperfections  in  the  preservation  of  the  surface  layer  of  the  shell. 
Like  Peron,  I  have  seen  no  specimen  of  the  right  valve. 

Examples  of  this  species  are  pi-eserved  in  the  Norwich  Museum,  in  Dr.  Black- 
more's  collection,  and  in  Mr.  Brydone's  collection. 

Distribution. — Zone  of  Actlnocamax  quadratus  of  East  and  West  Harnham 
(Salisbury).  Zone  of  Belemnitella  mucronata  of  Clarendon  (Salisbury)  and  Norwich. 
Chalk  of  Trimingham. 

Genus — Aucella,  A.  Keyserlimj,  1846. 

('Eeise  iu  das  Petschora-Laud,'  p.  297.) 

Aucella  volgensis,  Lahusen,  1888.     Plate  X,  figs.  1  a-c,  2  a-c. 

1888.     Aucella  volgensis,  J.  Lahusen.     Ueber  die  russiseheu  Aucelleu  (Mora,  du 

Comitc  gcol.  Euss.,  vol.  viii.  No.  1),  p. 
38,  pi.  iii.  fi-,'s.  1—17. 

1896.  —  —         A.  P.  Pavlow.    Quart.  Journ.Geol.  See,  vol.  Iii,  p.  549, 

pi.  xxvii,  fig.  1. 

1896.  —  —         var.  eadiolata,  Pavlow.    Ibid.,  p.  650,  pi.  x.\vii,  fig.  2, 

Description. — Shell  large,  obliquely  ovate,  nnich  liigher  than  long,  moderately 
inflated,  with  regularly  curving  margin. 

Right  valve  of  moderate  convexity,  flattened.  Umbo  relatively  small,  and 
curving  only  slightly.  Anterior  ear  triangular,  with  n  dec]),  iiari'ow  byssal  siiuis. 
Posterior  ear  indistinctly  limited. 

Left  valve  very  convex  and  rounded,  the  dorsal  portion  continued  into  a  large 
and  prominent  umbo  which  curves  anteriorly,  Postero-ventral  part  of  valve  pro- 
duced and  somewhat  compressed. 

Surface  of  valves  with  concentric  growth-ridges,  sometimes  produced  into 
lamellfe,  and  forming  regular  curves. 

Measurements : 

(1)  (2) 

Length  ....         45         ..         36  mm. 

Height  of  left  valve  (oblique)         60         .         .         55     „ 
Thickness  (lioth  valves)         .         32         .         .         22     „ 
(1,  2)   Spilsby  Sandstone,  Donnington. 


70  CRETACEOUS    LAMELLIBRANCHTA. 

Affinities. — The  shell  in  this  species  is  larger,  relatively  higher,  more  oblique, 
and  less  inflated  than  in  .1.  Keijserlingiana  (see  below).  The  right  valve  is  more 
flattened,  and  its  umbo  is  only  slightly  curved.  The  umbo  of  the  left  valve  is 
larger  and  more  prominent. 

BemarJcs. — The  only  specimens  I  have  seen  are  internal  casts  from  the  Spilsb}' 
Sandstone.  The  example  of  this  species  described  by  Pavlow  as  var.  raiHolata 
shows  faint  radial  ribs  on  the  internal  cast  of  the  right  valve,  and  a  slight 
depression  on  the  left  valve  extending  from  the  umbo  to  the  postero-ventral 
margin  (Plate  X,  fig.  2). 

Types. — From  the  Upper  Volga  beds  of  Kaschpur  (Simbirsk),  Staraja-Rjasan, 
and  Olenek.  The  specimens  figured  l)y  Pavlow  are  in  the  Sedgwick  Museum  and 
are  here  re-figured. 

Bislriliitiov. — Spilsby  Sandstone  (zone  of  Belemnites  lateralis)  of  Donnington. 


AucELLA  KETSEELmGiANA,  TrautschoU,  1868.     Plate  X,  figs,  oa — d,  'ia,h,  5. 

1837.     In.oceeamus  concentricus,  G.  Fischer  de   Waldhetni.     Orvctographie  clu 

gouvernm.  de  Moscou,  p.  177, 
pi.  XX,  figs.  1 — 3. 
1846.     AxjCELLA  CONCENTRICA,  vcir.  EUGOSA,  A.  Kei/gerlimj.    Eeise  in  das  Petscbora- 

Laud,  p.  300,  pi.  xvi,  fig.  16. 
18.50.     AvicuLA  (Buchia)  n.  sp.,  F.  Homer.     Neues  Jalirl).  fiir  Miu.,  etc.,  p.  393. 
1868.     AucELLA  Keyseelingiana,  H.  TrautschoJd .     Verluiudl.  d.  russisch-kaiser- 

licli.    iiiiueral.   Gresellscli.   in    Peters- 
Imrg,  ser.  2,  vol.  iii,  p.  250. 
1874.  —         CONCENTRICA,  var.  EUGOSA,  F.  Totila.     Mesozoisch.  Yerstein.  v.  d. 

Kiihu-Iusel  (Die  zweite  deutsch. 
Nordpolf.,  in  1869,  1870,  iinter 
Kapitiin  K.  Koklcwev),  vol.  ii, 
p.  .503,  pi.  ii,  figs.  2,  3. 

1874.  —  —  var.  rugosissima,  F.  Tmila.      Ihid.,  p.  504,  pi.  ii, 

fig.  4, 

1875.  Perna  imbricatus  [Beau  MS.],  J.  PhUUpg,  Geol.  York?;.,  pt.  i,  ed.  3,  p.  247. 
—  —      VEN0STULUS  [Bean  MS.],  Phillips.     Ibid.,  p.  247. 

1884.     AvicuLA?   teutoburgiensis,  0.  Weerth.     Neocoui.   im  TeiitoKurg.  Walde 

(Palajout.  Abhaudl.,  vol.  ii), 
p.  50,  pi.  ix,  fig.  9. 

1886.     AucELLA  Keyseelingiana,  /.  Lahuseii.     Mem.  Acad.  Imp.  St.  Pt'tersbourg, 

ser.  vii,  vol.  xxxiii,  No.  7,  p.  4. 

1888.  —        Keyserlingi,  J.  Lahusen.     Ueber  die  riissischeu  Aucelleu  (Mt'm. 

Comite  geol.  Euss.,  vol.  viii.  No.  1), 
pp.  21,  40,  pi.  iv,  figs.  18—23. 

1889.  Inoceeamus  venustulus  et  imbricatus,  G.  W.  Lamj'luyh.     Quart.  Journ. 

Geol.  Soc,  vol.  xlv,  p.  615. 


AUCELLA.  71 

1896.     AucELLA  Keyseelingi,  a.  P.  Pavloxc.     Ibid.,  vol.  lii,  p.  550,  pi.  xxvii,  fig.  3. 

1899.  —  —  G.  Maas.     Zeitschr.  d.  deutsch.  geol.  Gresellscli.,vol. 

li,  p.  249. 

1900.  —  —  A.  Wollemann.     Die  Biv.  u.  Gastrop.  d.  deutsch.  u. 

iKilliiiid.  Neoeoins  (Alihandl.  d. 
k.  preussisch.  geol.  Land.,  N.  F., 
pt.  31),  p.  56,  pi.  ii,  figs.  6—9. 

1901.  —  —  J.  F.  PompecJcj.     Neues  Jahrb.  fiir  Min.,  etc.,  Beil.- 

Bd.  xiv,  p.  319,  pi.  XV,  figs.  3,  6. 
8—10,  13,  14,  17,  18,  20,  21. 
1903.  —  —  A.  Wollemann.   Zeitschr.  d.  deutsch.  geol.  G-esellscb., 

vol.  Iv,  p.  34  (Briefl.  Mittcil.). 

Description. — Shell  of  moderate  size,  oljlique,  with  more  or  Ics.s  triangular  out- 
line and  rounded  margins,  higher  than  long,  inflated.  Umbones  prominent,  at  the 
anterior  end  of  the  hinge-line,  almo.st  touching,  curved  inwards  and  forwards. 

Right  valve  convex  in  the  neighbourhood  of  the  umbo,  but  usually  flattened 
elsewliere.  Anterior  ear  close  to  the  umbones,  triangular,  convex,  narrow  where 
united  to  the  rest  of  the  valve,  with  a  deep  and  narrow  bjssal  sinus.  Posterior 
ear  longer,  but  indistinctly  limited. 

Left  valve  mucli  more  convex  than  the  right  valve,  especially  in  the  dorsal  part, 
somewhat  compressed  posteriorly ;  greatest  convexity  between  the  umbo  and  the 
postero-ventral  extremity.  Umbo  more  prominent  than  in  the  right  valve.  Ears 
indistinctly  limited. 

Both  valves  ornamented  with  many  narrow,  concentric  lamelhv  wliich  are 
placed  more  or  less  vertically  to  the  surface  and  are  separated  by  broad,  flat 
interspaces.  The  lamellfe  occur  at  faii'ly  regular  intervals,  but  the  distance 
between  them  varies  on  different  parts  of  the  shell.  They  curve  gently  on  the 
median  part  of  the  valve,  but  bend  more  sharply  in  passing  on  to  the  anterior 
and  posterior  parts,  where  they  become  closer  to  one  another.  The  lamellae 
have  often  disappeared  from  the  parts  near  the  umbones. 

Measurements  : 

(1)  (2)  (3)  (4) 

Length  .         .         31         .         28         .         24         .         18  mm. 

Height   .         .         39         .         o2         .         30         .         24     „ 
Thickness       .         —         .         IC         .         16         .         12     „ 
(1 — 4)  Claxby  Ironstone,  Claxby. 
Acuities. — See  Aucella  volgensis  (p.  09). 

Ti/pe. — The  specimens  figured  by  Pavlow  are  in  the  Sedgwick  Museum. 
Distribution.— C\a\hy    Ironstone     (zone    of     Belenmites   lateralis)    of    Cla.xby. 
Speeton  Clay  (zone  of  Delenmites  jaciilnm)  of  Speeton, 


72  CRETACEOUS   LAMET.IJHRANCHIA. 

Genvs — Aticei.i.ina,  ./.   F.    I'cinperlj,   I'.lOl. 
('  Neues  Jalirb.  fiir  Miii.,'  etc.,  Beil.-Bd.  xiv,  p.  365.) 

AucELLiNA  GRTPH^oiPES    (Sowevhy),    183().       Plate  X,  figs.  (3«  —  il,  7n — r,  8a,li, 

9rt— f,  10— l:]. 

1836.     AvicuLA  GEYPH.«:oiDES,  /.  de  C.  Soiverby.     Trans.  Geol.  Soc,  ser.  2,  vol.  iv. 

pp.  156,  335,  pi.  xi,  fig.  3. 
1841.  —  —  F.    A.    Bl'imer.      Die   Versteiu.    d.    norcl  -  deutseh. 

Kreidegeb.,  p.  64,  pi.  viii,  fig.  16. 
1846.     Inoceramus  Co(iUA>DiANUS,  A.  (VOrbigny.     Pal.  Franc.  Terr.  Crct.,  vol.  iii, 

p.  505,  pi.  cccciii,  figs.  6 — 8. 
1850.  _  _  —  Prodr.  de  Pal,  vol.  ii,  p.  139. 

1853.  AtrcELLA   gryph^oides,   A.    v.    Strombecl-.      Zeitschr.   der   deutseh.    geol. 

Gesellsch.,  vol.  v,  p.  500. 

1854.  AvicuLA  —  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  163. 

1856.     AucELLA  —  A.  V.    Strombeck.      Zeitschr.    der   deutseh.    geol. 

GeseUsch.,  vol.  viii,  p.  488. 
1864.  —  --  H.  Bolsche.     Neues  Jahrb.  fiir  Min.,  etc.,  p.  669. 

1869.     Inoceeamtis  CoQUANDiANrs,  F.  J.  Picfet  and  G.  Campiche.    Foss.  Terr.  Cret. 

Ste.  Croix  (Mater.  Pal.  Suisse, 

ser.  5),  p.  Ill,  pi.  clx,  figs.  9, 10. 

1875.     AvicuLA  GRYPHJEOiDEs,  A.  J.  J tikes-Brovjne .     Quart.  Jouru.  Geol.  Soc,  vol. 

xxxi,  p.  298. 
1882.  —  —  R.    Windmi'iUer.      Jahrb.   d.    k.    preussisch.     geol. 

Laudesaust.  fiir  1881,  pp.  20,  21. 
1893.  —  —  A.    V.    hUroiiihfck.      Zeitschr.    der    deutseh.    geol. 

Gesellsch.,  vol.  xlv,  pp.  490,  493. 
1895.  —  —  E.  Tiessen.     Zeitschr.  der  deutseh.  geol.  Gesellsch., 

vol.  xlvii,  p.  478. 
1899.     AucELLA  CoQUANDi,  1).  J.  Aiithida.     Kreidefoss.  des  Kaukasus  (Beitr.  z. 

Paliiout.  u.  Geol.  Osterr.-Ungarns  u. 
d.  Orients,  vol.  xii),  p.  78. 

1901.  AuCELLiNA  GRYPH^oiDES,  J.   F.  Pompeckj.      Ncues  Jahrb.  fiir  Min.,  etc., 

Beil.-Bd.  xiv,  pp.  354,  365, 
pi.  xvi,  figs.  6 — 8. 

1902.  —  —  A.  WoUenitiini.     Liiueljurg.  Kreide  (Abhandl.  il. 

k.  preussisch.  geol.  Landesaust.,  N.  F., 
Heft  37).  ]).  64,  pi.  iii,  figs.  2,  3. 

Non  1829.     Avicula  J.  de  C.  Soi'-i'rby.     Trans.  Geol.  Soc,  ser.  2,  vol. 

iii,    p.    119    [Pseiidomoitiitis 
speiu H carta  ( Schlotheim)  ] . 
?  Non  1847.  —  —  J.  Midler.     Petref.  der  Aachen.  Kreidef.,  pt.  1, 

p.  29. 


AUCELLINA.  73 

Description. — Shell  oval,  very  obli(|ue,  very  incciuivalve  ;  dorsal  pai-t  of  posterior 
margin  more  or  less  straightened,  the  remaining  margins  forming  a  regular  curve. 

Right  valve  flattened,  but  convex  near  the  umbo ;  height  and  length  nearly 
equal.  Umbo  small,  near  the  middle  of  the  hinge-line,  curving  slightly.  Hinge- 
area  obtusely  triangular.  Anterior  ear  long,  triangular,  with  a  very  deep,  narrow, 
curved  byssal  sinus  on  each  edge  of  which  is  a  row  of  tubercles.  Posterior  eai- 
usually  of  about  the  same  length  as  the  anterior  ear,  but  indistinctly  limited,  with 
the  outer  angle  obtuse. 

Left  valve  convex,  especially  the  dorsal  part,  more  compressed  postero-ven- 
trally,  sometimes  with  a  shallow  sulcus  extending  from  the  umbo  to  the  postero- 
ventral  extremity.  Dorsal  portion  of  the  valve  produced  into  a  lai-ge,  prominent, 
much  curved  umbo.  Hinge-area  obtusely  triangular.  Posterior  car  larger  than 
the  anterior,  with  a  rounded  depression  between  it  and  the  umbo  ;  anterior  ear 
short,  triangular. 

Ornamentation  consists  of  numerous  concentric  growth-lines  which  sometimes 
become  lamellar,  and  are  separated  by  flat  interspaces.  Small,  close-set,  radial 
ribs  occur,  especially  in  the  neighbourhood  of  the  umbo. 

Measurements  of  left  valve  : 

(1)  (2)  (3)  (4)' 

Length  .  .         22         .         21  .  18         .         14  nnn. 

Height  (oblique)     29         .         27         .         25         .         17     „ 

(1 — 4)  Cambridf^e  Greeusand. 

Affinities. — The  probable  relationship  of  this  species  to  Aucella  has  l)een 
pointed  out  by  von  Strombeck,  Stoliczka,  and  .lukes-Browne.  Recently  its 
affinities  to  Fseudomonotis  and  Aucella  have  been  fully  discussed  by  Prof. 
Pompeckj,  l)y  whom  the  genus  Aucellina  has  been  established  to  include  Avicida 
aptiensis,  d'Orbigny,  and  Avicula  (jri/phieoidcs,  Sowerby.  Anrellina  is  very  closely 
allied  to  Aucella,  but  differs  from  it  in  the  absence  of  an  articulating  groove  in 
the  hinge-area  of  the  left  valve. 

Inoceramus  Goquandianns,  d'Orbigny,  was  regarded  by  Jukes-Bi-ownc  as  identical 
with  Aucellina  riri/phasoides,  and  1  agi'ee  with  that  view.  Tlie  identity  is  also  suji- 
ported  by  the  fact  that  Pictet  and  Campiche  referred  the  specimens  fouTid  in  (lie 
Cambridge  Greonsand  to  Inoceramus  Coquandiainis. 

Types. — I  have  not  seen  the  types;  Fitton  stated  that  they  were  in  the 
collection  of  Mrs.  Murchison,  and  came  from  the  Upper  Greeusand  of  Nurstt^-d 
and  Cambridgeshire  (?  Cambridge  Greensand). 

Distribution. — Up])er  Gault  of  Folkestone  and  Eastbourne.  Red  Limestone  of 
Hunstanton  and  Speeton.     Cambridge  Greensand  (derived). 

L'^^pper  Greensand  (zone  of  8chlaml>achia  mstrata)  of  Hanqishire,  Devizes,  and 
near  Didcot ;   (zone  of  Fecten  asper)  of  Okeford  Fitzpaine  and  ^Varminster.     Cani- 

10 


74  CRETACEOUS   LAIilELLIBllANCHIA. 

bridge  Grecnsaiicl  (indigenous).  Cliloritic  Marl  of  Maiden  Bradley,  Devizes, 
Isle  of  Wight,  Urchfont  (Wilts),  Holj^bourne  (Hants),  and  Eastbourne.  Chalk 
Marl  (zone  of  Schloenbachia  varians)  of  the  Isle  of  Wight,  Folkestone,  Hunstanton, 
Lincolnshire,  and  Yorkshire.  Totternhoe  Stone  of  Fulbourn  and  BurweU.  Zone 
of  Uolaster  sulnjlohosus  (above  Totternhoe  Stone)  of  Eversden  (Cambs.). 


Fa,}iUi/—¥E'Rm'DM,  Zittel. 
Genus — Geuvillia,  M.  J.  L.   Dcfrance,  1820. 

('Diet.  Sci.  nat.,'  vol.  xviii,  p.  502.) 

Gervii,li.\    sublanceolata   (cVOrhiijny),  1850.      Plate  X,  figs.   14 — 10;    Plate  XI, 

fig.  1.     Text  figures  7,  8. 

1826.     Geevillia  aviculoidks,  J.  de  C.  Sowerhy.     Miu.  Couch.,  vol.  vi,  p.  lO,  pi. 

dxi,  figs.  1,  2,  3,  5  (not  4),  [uou  Periia 
aviculoicles,  Sowerby,  1814]. 

1845.  —  —  E.  Forbes.     Quart.  Jouru.  Geol.  Soc,  vol.  i,  p.  24(5. 

—  AvicuLA  LANCEOLATA,  —  Ibid.,  p.  247,  pi.  iii,  fig.  8. 
1850.           —        SUBLANCEOLATA,  A.  d'Orhujuij.     Proilr.  de  Pal.,  vol.  ii,  p.  119. 

1853.  Gervilia  alpina,  F.  J.  Pidd  and  W.  Roux.     Moll.  Foss.  Gres  verts  de 

Geneve,  p.  496,  pi.  xli,  fig.  3. 

1854.  Gervillia  anceps,  J.  Morris.     Cat.  Brit.  Foss.,  ed.  ii,  p.  167. 

—  AvicoLA  LANCEOLATA,  Morris.     Ibid.,  p.  163. 

1858.     Gervilia  anceps,  F.  J.  Fidet  and  E.  Eenevier.    Foss.  Terr.  Ajitien  (Mati'r. 

Pal.  Suisse,  ser.  1),  p.  121 , 
pi.  xvii. 
1865.  —  —       H.  Coquand.     Mon.  Aptieu  de  I'Espague,  p.  145. 

1869.  —        ALPINA,  F.  J.  Firtd  and  G.  Cainpiche.     Foss.  Terr.  Cret.  Ste.  Croix 

(Mater.  Pal.  Suisse,  ser.  5), 
p.  83,  pi.  civ,  figs.  2—4. 
1902.     Gervilleia  anceps,  F.  Freeh.    Centralb.  fiir  Miii.,etc.,  p.  612  (text-figure). 

Dcticription. — Shell  elongate,  very  oblique,  slightly  inecjuivalve,  the  left  valve 
rather  more  convex  than  the  right.  Posterior  extremity  lanceolate,  but  rounded. 
Postero-dorsal  margin  slightly  sinuous.  Antero-ventral  marginal  parts  nearly  per- 
pendicular to  the  plane  lictween  the  valves  and  slightly  concave.  Umbones  incon- 
spicuous, almost  terminal.  Only  a  very  small  portion  of  the  valve  is  seen  in  front 
of  each  umbo;  on  the  left  valve  this  portion  is  bounded  by  a  linear  depression,  but 
on  the  right  valve  it  is  not  limited.  Tlie  median  part  of  each  valve  is  convex,  but 
becomes  compressed  towards  the  posterior  extremity.  Between  the  convex  portion 
and  the  hinge-line  (posterior  to  the  umbo)  is  a  long,  triangular,  compressed,  wing- 
like portion,  of  which  tlie  inner  boundary  is  not  limited,  and   tlie  posterior  margin 


GERVILTJA. 


75 


is  slightly  convex  or  sometimes  almost  straight ;  on  this  part  the  growth-lines  are 
convex  posteriorly  and  cnrvc  towards  the  nmbo,  except  in  young  specimens  where 
tla-y  curve  posteriorly  as  thoy  approacli  the  hinge-line. 

Hinge-line  long,  forming  rather  less  than  half  the  greatest  length  of  the  valve, 


I   I   !>"> 


\SJ 


^S'l 


He^ 


'-/^^'> 


FiQ.  7.—Gernllia  suhlanceolata  (d'Orbifpiy.)     Lower  Gieonaaml  (Crackers),  Athorfiold.      Seilj^ict  Museum. 
X  j.     a,  left  valve ;  b,  antero-dorsal  view  of  another  specimen  ;  c,  left  valve  of  another  specimen. 


and  making  an  obtuse  angle  with  the  posterior  margin.  Ligament  pits  large, 
usually  from  six  to  nine  in  number,  placed  at  nearly  equal  distances,  and  usually  of 
nearly  equal  size,  except  the  anterior  and  posterior,  whicli  may  be  smaller  than  the 
others. 

Surface  of  valves  ornamented  with  growth-lamellae  only. 


(5) 

(0) 

(7) 

(8) 

(9) 

74 

G6 

41 

54 

41mm. 

152 

149 

89 

110 

86  „ 

76  CRETACEOUS  r.AMEETJBRANCHIA. 

Measurements : 

(1)  (2)  (3)  (4) 

Hinge-line    .         .         .         .     92       86       86       83 
Umbo  to  posterior  extremity  182     200     182     163 

(1 — 7)  Crackers,  Atherfiekl. 
(8,  9)  Greensand,  Blackdown. 

Affinities. — Gervillia  snhlanceolata  is  closely  allied  to  G.  anceps,  Deshayes,'  of 
wliicli  tlie  types  are  from  the  Neocomian  of  Aube.  The  English  specimens  have 
usually  been  referred  to  the  latter  species,  biit  Pictet  and  Civmi)iclic  regarded  thcni 
as  distinct. 

The  characters  which  separate  the  two  species  are  (1)  tlic  antero-ventral  mai'giu 
is  concave  in  G.  suhhtnceolata,  whereas  in  G.  anceps  it  is  slightly  convex  or  almost 
straight;  (2)  the  posterior  margin  of  the  posterior  wing-like  part  is  convex,  or  in 
some  cases  nearly  straight,  and  the  growth-lines  on  tliis  part  of  the  shell  are  convex, 
whilst  in  G.  anceps  tlie  corresponding  margin  and  growth-lines  are  concave,  and  the 
wing-like  part  is  more  distinct ;  (3)  the  line  of  greatest  convexity — extending  from 
the  umbo  posteriorly — is  near  the  middle  of  the  valve  in  G.  suhlanceolata,  but  near 
the  antero-ventral  margin  in  G.  anceps  ;  (4)  it  is  possible  that  G.  suhlanceolata  is  less 
incquivalvo  tliaii  G.  avccps,-  but  at  present  tliis  point  cannot  l)e  prove<l,  since  only 
a  few  specimens  of  the  latter  species  showing  botli  vnlvcs  liavo  ])een  Found.  All  the 
examples  known  of  G.  am-c/is  appear  to  l)(^  larger  ami  to  Imvc  thicker  shells  than 
G.  t<ul)lauccolitla. 

I'ictetand  Campiehe  thought  that  (/.  ((iiccps  could  be  distinguished  by  the  second 
and  third  ligament  pits  being  close  together,  whereas  in  G.  siilihniccdlafa  the  pits 
are  nearly  equidistant.  An  examination  of  specimens  of  the  rornicr  shows  that  the 
position  of  the  second  and  thii'd  pits,  shown  in  d'Orbigny's  figure,  is  an  indixidiial 
variation,"  and  is  not  usually  found.  I'ictet  and  Cfimpiche  mention  as  another 
distinction  the  sharp  line  of  se})aration  between  the  posterior  wing  and  the  rest  of 
the  valve  in  G.  anceps;  although  this  feature  is  shown  in  d'Orbigny's  figure  it  is  not 
evident  in  the  specimens. 

G.  suhlanceolata  differs  from  G.  cosnenis,  de  Tjoriol,'  in  the  rapid  tapering  of 
the  shell  towards  the  posterior  extremity  and  in  the  less  extensive  development  of 
the  posterior  wing-like  part. 

Remarks. — Examples  of  this  species  from  Atherfiekl  were  described  and  figured 
as  Gervillia  alpina,  Pictet  and  Roux,  by  Pictet  and   Renevier  and  by  Pictet  and 

•  'Mc'm  Soc.  gcol.  de  France,'  vol.  v  (1842),  p.  9,  pi.  x,  fig.  3;  D'Orbigny,  'Terr.  Cret.,'  vol.  iii 
(1846),  p.  482,  pi.  cccxciv;  Pictet  and  Campiehe,  'Terr.  Crut.  Ste.  Croix'  (1869),  p.  82,  pi.  civ,  fig.  6. 

2  See  Desbayes'  fig.  3c. 

•''  The  probaliility  of  this  has  licen  mentioned  hy  E.  G.  Skeat  and  V.  Madson,  '  Jur.  Ncoc.  and 
Ganlt  Boulder.s  in  Denmark'  (' Dauniarks  geol.  Undersog.,'  vol.  ii,  No.  8,  1898),  p.  163. 

*  '  Gault  de  Cosne'  (1882),  p.  83,  pi.  ix,  figs.  21,  22. 


GERVILLIA. 


11 


Campiche.  The  specimen  figured  by  Pictet  and  Roux  is  not  sufficiently  perfect  to 
enable  us  to  state  whether  it  is  specifically  identical  with  G.  sithlduceohi fa,  hut  since 
Pictet,  Renevier,  and  Campiche  were  acquainted  with  the  type  and  other  specimens 
of  G.  alpinn,  and  had  also  good  specimens  from  Atherfield,  we  may  feel  every 
confidence  in  their  judgment  in  this  matter. 


Fio.  ».—GervilUa  suhlanceolata  {CCOxU^y).    Lower  Greonsand  (Crackers),  Atherfield.     Sodgivick  Museum. 
Eiglit  and  loft  valves  of  the  same  specimen,     x  J. 

A  young  individual  of  this  species  from  Atherfield  was  described  and  figured 
by  Forbes  as  Avicula.  lanceolata.  This  name,  however,  had  previously  been  em- 
ployed by  Sowerby  (1820)  for  a  species  from  the  Lias,  and  consequently  d'Orbigny 
altered  the  name  of  Forbes'  species  to  Avicula  sublancoolata.  Goldfuss  (18:30)  had 
also  used  the  name  Grrnllia  Inncmlata  for  a  species  from  the  IMiddle  Jvu-assic  of 
Wiirttemberg.    Since  d'Orljigny's  name  has  priority  over  GerrilHa  alpina  of  Pictet 


78  CRETACEOUS    LAMETJJRRAXCHIA. 

and  Roux,  the  species  now  iiiuler  consideration  must  be  known  as  Gervillia  suh- 
lanceolata  (d'Orbigny). 

The  yonng  individuals  of  G.  snblanceolata  differ  from  the  adults  in  that  the 
anterior  part  of  the  shell  is  relatively  longer  and  more  wing-like,  the  posterior  ear 
is  more  sharply  limited  and  its  growth-lines  are  concave  posteriorly,  and  tlio  valves 
are  more  unequal  (Plate  X,  figs.  14,  15). 

G.  anhlaiiceoJafa  belongs  to  Freeh's  '  Group  of  G.  aviciiloides.'  Freeh  gives  a 
figure  of  the  hinge  and  interioi'  of  a  specimen  from  Atherfield. 

I  am  greatly  indebted  to  Professor  Douvillc  for  the  opportunity  of  seeing  a 
specimen  of  Gervillia  anceps  from  Aube,  and  also  for  his  kindness  in  comparing  (/. 
snhlanccolata  with  the  specimens  of  G.  anceps  in  the  Ecole  des  Minos,  Paris. 

Ti/pes. — One  of  the  specimens  figured  by  Sowerby  (fig.  5)  is  in  the  British 
Museum  ;  the  others  (figs.  1 — 3)  cannot  be  traced.  Sowerby's  fig.  4  is  from  the 
Corallian  of  Shotover,  and  does  not  belong  to  this  species.  Avicuhi  lanceolata, 
Forbes,  from  the  Lower  Greensand  (pr()bnl)ly  Crackers)  of  Athei'tield,  is  in  tlie 
Museum  of  the  Geological  Society  (No.  2057).  The  type  of  llerrillia  dlpinn  came 
from  the  Gaidt  of  Saxonet. 

Disfrihiifion. — Lower  Greensand  (('rackers  and  Fitton's  Beds  20  and  15)  of 
Atherfield.     Atherfield  Beds  of  Sevenoaks. 

Recorded  by  To]dey  from  the  Atherfield  Beds  of  Haslemere,  Peasmarsh,  Shal- 
ford,  and  Redliill ;  fi'om  the  Hythe  Beds  of  Hythe,  Lympne,  Maidstone,  and 
Pull)orough  ;   and  from  the  Sandgate  Beds  of  Sandgate,  Folkestone,  and   Parliajn. 

Upper  Greensand  (zone  of  Srhhvnhncli'oi  roi<fr<if(i)  of  the  Tsle  of  Wight,  Black- 
down,  and   llaldon. 


Gervillia  i.tnoulotdes,  Forbes,  1845.     Plate  XI,  figs.  2-8. 

1845.     Gkrvillia  lingtjloides,  E.  Forbes.     Quart.  Joiirn.  Geol.  Soc,  vol.  i,  p.  246, 

pi.  iii,  fig.  9. 

—  AvicuLA  EPHEMERA,  Forhcs.     Ibid.,  p.  247,  pi.  iii,  fig.  6. 

184G.     Gervillia  linouloides,  A.  d'Orhigny.     Pal.  Fraii9.  Terr.  Crct.,  vol.  iii,  p. 

485,  pi.  cccxcvi,  figs.  1 — 4. 
1850.  —  —  d'Orbigny.     Prodr.  de  Pal.,  vol.  ii,  p.  119. 

AviC0LA  EPHEMERA,  —  Ibid.,  p.  119. 

1854.     Gervillia  linouloides,  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  107. 

—  AvicuLA  ephemera,  Morris.     Ibid.,  p.  163. 

1858.     Gervillia  linouloides,  F.  J.  Pidet  and  E.  Renevier.     Foss.  Terr.  Ajitien 

(Mater.  Pal.  Suisse,  ser.  1), 
p.  123,  pi.  xviii,  figs.  3,  4. 

1869.  —  —  F.J.Pictetand  G.Campiche.    Foss.  Tern  Cret.  Ste. 

Croix  (Mater.  Pal.  Suisse, 
ser.  5),  p.  91. 


GERVILLIA.  79 

Description. — Shell  small,  thin,  elongate,  compressed,  very  ol)li(|ue,  angular 
anteriorly,  truncated  posteriorly.  Left  valve  more  convex  than  the  right.  Um- 
bones  almost  terminal.  Ligament  area  narrow,  with  four  or  five  pits,  one  of  which 
is  under  the  umbo.  Anterior  part  of  the  shell  very  small,  compressed.  Median 
part  flattened.  Postero-dorsal  part  relatively  large,  compressed,  wing-like.  On 
the  left  valve  a  rounded  ridge  extends  from  the  umbo  to  the  postero-veutral  angle ; 
below  this  ridge  the  shell  is  bent  sharply. 

Surface  smooth,  or  ornamented  with  concentric  lines. 

Measurements  : 

(1)  (2)  (3) 

Length  of  hinge       .         .         .     lo'o      .         \b         .         lo  mm. 
Umbo  to  postero-ventral  angle     23         .         29         .         25     „ 
(1—3)  Crackers,  Atherfield. 

Affinities. — G.  recta,  Meek  and  Hayden,'  from  the  Fox  Hill  Beds  of  the  Upper 
Missouri,  is  closely  allied  to  this  species.  The  imperfectly  known  Gervillia  Reichi, 
Romer,^  resembles  G.  linguloides,  but  appears  to  have  the  posterior  wing  more 
distinctly  limited. 

In  the  form  of  its  shell  G.  Ihujuluides  resembles  some  of  the  species  of  Pteria 
which  belong  to  the  sub-genus  Pseudoptera  (see  p.  63),  but  the  presence  of  liga- 
ment pits  proves  it  to  be  a  Gervillia. 

Bemarks. — Pictet  and  Renevier  showed  that  Avicida  ephemera,  Forbes,  is  only 
an  internal  cast  of  Gervillia  linguloides. 

This  species  occurs  commonly  in  the  Orackers  of  Atherfield  auel  is  grt'gai-ious. 

Types. — From  the  Crackers  of  Atherfield,  in  the  Museum  of  the  Geological 
Society  (Nos.  20-iO,  2054).  The  types  of  Avicula  ephemera,  also  from  Atherfield, 
are  in  the  same  collection  (Nos.  2051,  2052). 

Distribution. — Lower  Greensand  (Crackers)  of  Atherfield.  Recorded  by  Topley 
from  the  Atherfield  Clay  of  Peasemarsh  and  Shalford. 


Gi;i!\  iLi.iA  AL.i',Rii;.\iis  ((S'(*/n/7;//),  Isl'.l.      i'latc  XI,  figs.  [hi-(l,   lOft-//,    11.     Te\l- 

figures  9-14. 

1810.     MoDiOLA  ?  Aii^FORMis,  /.  Soxoerhij.    Mill.  Coiicli.,  vol.  iii,  p.  03,  i>l.  ccli. 

183.5.     Pekna  ALiFOBMis,  Sowcrbij.     Ibid.,  vol.  vi,  systematical  iudi-x,  \>.  243. 

1845.  —  ALiKFOKMis,  E.  Forbfs.  Quart.  Jouru.  Geol.  Soc,  vol.  i,  p.  '2-k),  pi.  iii. 
fig^^^ _ 

»  '  Proc.  Acad.  Nat.  Sci.  Pliilad.'  vol.  xiii  (1861),  p.  441.   F.  B.  Meek,  '  Invert.  Cret.  and  Tert.  Fobs. 

U.  Missouri '  (187(3),  p.  66,  pi.  xxix,  fig.  1  a,  b. 

-  'Die  Versteiu.  d.  uord-deutscli.  Kreidegeb.'  (1841),  p.  64,  pi.  viii,  fig.  14  (uamed  G.   CotUv   ou 
pi.  viii). 


80 


CRETACEOUS    LAMELLIBRANCHIA. 


1846.     Geevilia  al^efoemis,  A.  d'Orhiyny.     Pal.  Frau^.  Terr.  Crt't.,  vol.  iii,  p.  484, 

pi.  cccxcv,  figs.  1 — 3. 
1850.  —  —  (TOrhiijnij.     Prodr.  de  Pal.,  vol.  ii,  p.  82. 

1852.  AvicuLA  Ehodani,  F.  J.  Pidd  and  W.  lioux.     Moll.  Foss.  Gres  verts  de 

Geneve,  p.  494,  pi.  xli, 
fig.  2. 
1854.     Geevillia  al^efuemis,  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  167. 

1853.  Geevilia  alifoemis,  F.  J.  Fidel  and  E.  Renevier.  Foss.  Terr.  Aptien  (Mater. 

Pal.  Suisse,  ser.  1),  p. 
120,  pi.  xviii,  figs.  1,  2. 
1865.  —  -         H.  Coquand.     Moii.  Aptieii  de  I'Espagne,  p.  144. 

1869.  —  —         F.  J.  Fidd  ami  G.  Cumjnche.     Foss.  Terr.  Crct.  Ste. 

Croix  (Matt'r.  Pal.  Suisse,  ser. 
5),  p.  86,  pi.  clvi,  fig.  1. 
1871.     Geevillea      —         F.  Stoliczka.     Palseoiit.  Indica,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  399. 

Description. — Shell  thick,  large,  much  inflated,  triangular  or  rhombic,  oblique. 


FlQ.  9.—Gervillia  al:i-formis  (Soworby).     Lowt-r  Grucusaud  (Crackers),  Athorfield.    Sedgwick  Musuuiu. 
Dorsal  view,  showing  the  ligament  area  of  the  right  valve.     Natural  size. 

Anterior  parts  of  l)oth  valves  more  or  less  nearly  vertical  to  the  plane  of  the  valves. 
Around  the  byssal  opening  the  marginal  parts  of  the  valves  are  sometimes  concave. 
Umbones  near  the  anterior  extremity.  Hinge-area  large  with  large  ligament  pits 
— usually  five  or  six.     Numerous  narrow  transverse  teeth. 

Left  valve  larger  and  more  inflated  than  the  right,  with  its  umbo  strongly 
incurved.  A  very  prominent,  convex  portion  extends  from  the  umbo  to  the 
rounded  postero-ventral  extremity ;  dorsally  it  bends  anteriorly ;  ventrally  it  has 
a  slight  posterior  curvature.      Tliis  convex  part  is  separated  by  a  .shallow  depres- 


GERVILLTA. 


81 


sion  from  a  small  anterior  portion,  and  l)y  a  lineai'  depression  from  a  very  large 
triangular  posterior  portion,  wliicli  is  flattened  in  small  specimens  but  moderately 
convex  in  older  examples.  This  posterior  portion  lias  a  wing-like  projection  in 
young  specimens,  but  in  older  forms  its  posterior  border  is  nearly  straight  and 
forms  an  obtuse  angle  with  the  hinge-line. 

Right  valve  similar  to  the  left,  but  smaller,  less  convex,  with  the  posterior 
portion  more  flattened,  and  with  the  umbo  nut  incurved. 

Ornamentation  in  the  adult  shell  consists  of  mimerous  growth-lamella}.  On 
the  earlier  part  of  the  shell,  and  in  young  exam])l(>s,  there  are  :i  few  rather  strong, 
broad,  rounded  radial  rilis  with  a  few  smaller  ribs  between. 


Fio.  10.— Gei-fiHia  aJ.T/ormis  (Soworby).     Loft  valve  of  specimen  shown  in  Fig.  9.      x  J. 


Measurements 


Length  of  hinge 
Height  (oblique) 


(1)  (2) 

97         .         00 
122         ..       130 
(1_3)  Crackers,  Atherfield. 


(3) 
85  mm. 

116     „ 


Affimties.— This  species  presents  some  resemblance  to  G.  nllnjidiensis 
(Matheron')  but  is  more  inflated,  less  inequivalve,  and  less  oblique. 

Pictet  and  Campiclie  regarded  the  form  figured  as  G.  aJxformh  by  d'Orbigny  as 
distinct  from  Sowerby's  G.  alseformis,  and  they  believed  that  the  former  was  limited 
to  the  Neocomian  whereas  the  latter  occurs  in  the  Aptian.  Some  specimens  from 
the  Pmia-bed  of  Atherfield  agree  almost  exactly  with  d'Orbigny's  figure,  and  I 

1  '  Catal.  Fobs,  des  Bouches-du-Khone '  (1842).  p.  175,  pi.  xxvi,  fig.  1 ;  Pictet  and  Campiche,  •  Terr. 
Crot.  Ste.  Croix'  (18G9),  p.  81,  pi.  civ,  fig.  1. 


82 


CRETACEOUS   LAMETJJT5RAXCHTA. 


/. 


Fig.  11. — Gervillia  nlse/ormis  (Sowerby).     Right  valvp,  and  uinlio  and  ligament  area  of  the  left  valve 

of  the  siiecimen  shown  in  fif:fs.  !>,  10.      x   J. 


Fios.  12,  l.'i. — Gervillia  alirformis  (Sowerby).      Lower  Grecnsancl  (Craclcers),  Atherfield.     Sedgwick 
Museum.     12.  Left  valve.     13.  Rii,'ht  valve,      x  J. 


GERVILLIA. 


83 


cannot  regard  them  as  more  than  a  variety  in  which  tlic  central  convex  part  is 
rather  narrower  and  more  elevated  than  usual  (fig.  14). 

Rcinarls. — G.  al.'vforinu  belongs  to  Freeh's  ^  '  Group  of  GeroUlia  ITarlmanni,'  in 
which  the  shell  is  obliquely  rhombic  and  has  numerous  small  teeth. 

Young  specimens  of  G.  alxformis  differ  from  older  examples  in  having  well- 
marked  radial  ribs,  in  the  valves  being  less  inflated,  and  in  the  occurrence  of  a 
wing-like  projection  on  the  posterior  ear.  They  resemble  the  form  described  by 
d'Orbigny  as  Avicula  GottahUna,  but  in  the  latter  the  radial  ornamentation  and 
well-marked  posterior  wing  are  retained  in  the  adult  state,  whereas  they  soon 
become  obsolete  in  G.  ala'formis.  I  am  not  accjuainted  with  the  character  of  the 
hinge  of  Avicula  Guttaldina. 


Fiu.  14.—GervilliaaLv/ormis  (Soworhy).     Lower  Greoiisaiul  (/'(.(•Ha-bed),  Atherfield.     Sedgwick  Museum. 

Loft  valve  of  a  narrow  varioty.      x  J. 

Ti/pr. — The  type  cannot  be  found  ;  it  came  from  the  Lower  Greensand  (prolj- 
ably  the  Fenia-hed)  of  Sandown,  Isle  of  Wight. 

Distribution. — Perna-hed  of  Atherfield  and  Sandown.  Crackers  and  Bed  1 1 
(of  Fitton)  of  Atherfield.  Atherfield  Clay  of  Haslemcre.  Hythe  Beds  of  Hythe 
and  Lympne. 


Gervilllv  rosteat.v  (Soicerbij),  1830.     Plate  XI,  figs.  12  a,  A,  13-23. 

183G.     Peuna  rosteata,  /.  de  C.  Sowerbij.     Traus.  Gool.  Soc,  scr.  2,  vol.  iv.,  pp. 

241,  342,  pi.  xvii,  fig.  17. 
1846.     Avicula  cenomanensis,  A.  d'Orbigny.     Pal.  Fran9.  Terr.  Orel.,  vol.  iii,  p. 

476,  pi.  cccxci,  figs.  11—13. 
1850.  —  —  d'Orbigny.     Prodr.  de  Pal.,  vol.  ii,  p.  167. 


1  'Ceutralb.  fur  Min.,'  etx;.  (1902),  p.  613. 


(4) 

(5) 

18 

15  mm. 

20 

17     „ 

84  CRETACEOUS    LAMELI.JBRANCHIA. 

1850.     Pkkna  eostrata,  cVOrhifjnij.     Ibid.,  p.  168. 
1854.     Gervillia  —        J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  168. 
1871.     Melina        —         F.  Stoliczka.     Palseout.   Indica,  Crct.  Faumi    S.  India, 

vol.  iii,  p.  400. 
?  1895.     AvicuLA  cf.  cenomanensis,  E.  Tiessen.   Zeitschr.  d.  deutsch.  geol.  Gesellscb., 

vol.  xlyii,  p.  479. 

Description. — Shell  rather  small,  of  moderate  convexitj'-,  often  very  oblique, 
triangular.     Ventral  and  posterior  margins  rounded.     Hinge-line  long. 

Left  valve  more  convex  than  the  right,  with  the  umbo  moderately  incurved. 
The  large,  central,  very  convex  portion  is  indistinctly  separated  from  the  large, 
anterior,  triangular,  wing-like  ear  and  from  a  narrow,  flattened,  obtusely  triangular 
posterior  part. 

Right  valve  similar  to  the  left  but  less  convex  and  with  the  umbo  only  slightly 
incurved,  and  with  the  anterior  ear  more  distinctly  limited. 

Surface  of  valves  with  narrow,  regular  growth-layers. 

Measurements  : 

(1)  (2)  (3) 

Length  of  hinge     .         21  .         20         .         20         . 

Height  (oblique)    .         25         .         28         .         24         . 

(1 — 5)  Greeusand,  Blackdowu. 

Affinities. — Avicula  cenomanensis,  d'Orbigny,  from  the  Cenomauian  of  Le  Mans, 
appears  to  be  identical  with  G.  rostrata.  In  all  the  specimens  of  the  latter  which 
I  have  seen,  the  terminal  portion  of  the  posterior  wing  is  more  or  less  imperfect, 
but  the  growth-lines  show  that  the  posterior  margin  must  have  had  the  same  form 
as  in  d'Orbigny's  fig.  11. 

Gervillia  rostrata  presents  some  resemblance  to  the  young  fonn,s  of  G.  alieformis 
(p.  79)  but  is  more  oblique  and  without  radial  ribs,  also  the  central  convex 
portion  is  less  sharply  marked  off  from  the  lateral  parts,  and  the  anterior  ear  is 
larger. 

G.  rostrata  is  allied  to  G.  tciiuicostala,  Pictet  and  Campiche  (see  below),  but  the 
right  valve  is  less  flattened,  and  the  concentric  ornamentation  appears  to  be  less 
developed — this,  however,  may  be  due  to  difference  of  preservation,  since  some 
of  the  Blackdowu  specimens  are  neai'ly  smooth  whereas  others  show  di.stinct 
concentric  ridges. 

Remarks. — This  species  is  moderately  common  at  Blackdowu  but  is  usually 
imperfectly  preserved.  An  example  from  the  Gault  of  Folkestone,  recorded  by 
Price  as  Avicula  cenomanensis,  is  probably  referable  to  this  species,  but  the  greater 
part  of  the  shell  has  disappeared,  leaving  a  mould  of  the  right  valve ;  the  specimen 
is  now  in  the  Museum  of  Practical  Geology  (No.  1(324). 

The  examples  of  G.  rostrata  show  a  considerable  amount  of  variation  in  ul)li(|uity. 


GERVILLIA.  85 

and  some  of  the  less  oblique  specimens  (Plate  XI,  figs.  17,  18)  appear  at  fii'st 
siglit  to  be  distinct  from  the  more  abundant  oblicpic  forms,  but  there  is  a  comijlete 
transition  between  the  extremes. 

Didrihation. — Upper  Greensand  (zone  of  Schhciihachia  roslrata)  of  Blackduwn, 
Haldon,  and  ?  Devizes.     ?  Upper  Gault  (zone  xi)  of  Folkestone. 


Gervilija,  sp.     Plate  XI,  figs.  24,  25. 

Specimens  from  the  Ferruginous  Sands  of  Shaiiklin,  whicli  were  collected  by 
the  late  0.  J.  A.  Meyer  aud  are  now  in  the  Sedgwick  Museum,  resemble  closely 
G.  rostrata  and  G.  tenuicostata  (Pictet  and  Campiche),^  but  the  material  at  present 
available  is  hardly  sufficient  to  justify  a  definite  conclusion  as  to  their  relationship. 
The  specimen  from  the  Lower  Greensand  of  Upware  figured  l)y  Keeping"  as 
Perna  sp.  nov.  resembles  still  more  closely  some  examples  of  G.  rostrata ;  the 
original  is  in  the  collection  of  Mr.  J.  F.  Walker. 


Gekvillia  Foebesiana,  tVOrhigiuj,  184G.    Plate  XI,  figs.  2G,  27.    i'late  Xli,  figs.  1-5. 

1826.     Gekvillia  solenoides,  /.  de  C.  Sowerhy.     Mill.  Coiicli.,  vol.  vi,  p.  1-i,  id.  dx, 

figs.  1—3  (not  4). 

1845.  —  —  E.  Forbes.     Quart.  Jouru.  Geol.  Soc,  vol.  i,  \).  '2U>. 

1846.  —         FoBBESiANA,  A.  cVOrhiijnij.     Pal.  Trau^.  Terr.  Crct.,  vol.  iii,  p. 

486,  pi.  cccxcvi,  figs.  5,  6. 
1850.  —  —  d'Orbiynij.     I'rodr.  de  Pal.,  vol.  ii,  p.  119. 

1854.  —         SOLENOIDES,  J.  Morris.     Cat.  Brit.  Poss.,  ed.  2,  p.  168  (jjarliiii). 

1897.  —         FoRBESiw A,  E.  B.  Newton.     Proc.  Dorset.  Nat.  Hist,  aud  Antiq. 

Field  Club,  vol.  .wiii,  p.  87. 

Descrijjliun. — Shell  compressed,  slender,  greatly  elongated,  sabre-shaped,  taper- 
ing posteriorly  to  a  rounded  or  subtruncate  extremity.  Dorsal  margin  slightly 
concave ;  ventral  margin  convex,  with  a  rather  greater  curvature  than  the  dorsal 
margin.  Near  the  dorsal  margin  the  valves  are  compressed  rather  abruj)tly,  but 
ventrally  to  this  they  are  compressed  gradually,  giving  rise  to  a  knife-like  edge. 
Umbones  terminal,  acute.  Posterior  ear  large,  triangular,  with  its  dorsal  margin 
sti'aight  or  very  slightly  concave  and  its  posterior  margin  curving  backwards  so  as 
to  form  an  acute  angle  witii  the  dorsal  margin  of  the  valve.  The  ear  is  marked  by 
fine  growth-lines  parallel  with  its  posterior  border. 

'  'Terr.  Crct.  Ste.  Croix '  (1869;,  p.  88,  pi.  ulvi,  figs.  4,  5. 

■  'Foss.  Nooc.  Upware  aud  Brickhill"  (1883),  p.  109,  pi.  v,  fig.  3. 


86  CRETACEOUS    LAMELTJBRANCHIA. 

Surface  of  valves  siiiootli  exce])t  for  growth-i'idges,  of  wliicli  the  curved  portions 
near  the  dorsal  margin  are  more  distinct  than  the  other  jjortions. 

Hinge  with  small  transverse  teeth  at  the  anterior  end  and  six  or  seven  long 
narrow  obli(|ue  teeth  near  the  posterior  entl — the  latter  decreasing  m  length 
posteriorly. 

Measurements  .- 

(I)  (2)  (3)  (4) 

Height'         .         31         .         24         .         15         .         8  mm. 
Length-        .        182         .       125         .         71         .       35     „ 
(1—4)  Gault,  Folkestone. 

Affinities. — This  species  belongs  to  Freeh's  ■'  '  Group  of  (irrrillid  solejmidi'i:;.' 

The  only  locahties  given  for  G.  Forhesiana  by  d'Orbigny  ai-(j  Shanklin  and 
Athcrfield,  and  apparently  liis  figured  sj^ecimen  came  from  the  latter  place.  All 
the  examples  from  Shanklin  are  in  the  form  of  casts  of  which  the  posterior  part  is 
usually  missing;  it  is  consequently  difficult  to  make  out  their  real  charactei'S,  but 
they  probably  belong  to  this  species. 

The  examples  found  in  the  Gault  and  Upper  Greensand  differ  somewhat  from 
the  specimen  figured  by  d'Orbigny.  In  the  former  the  shell  is  less  slender  and 
tapers  more  quickly  posteriorly  ;  the  posterior  ear,  however,  agrees  with  d'Orbigny's 
figure. 

A  considerable  number  of  examples  of  Grrvillin  from  different  localities  and 
horizons  have  been  referred  by  various  writers '  to  G.  solenoides,  Defrance,^  but 
without  seeing  a  large  collection  of  those  forms  it  is  impossible  to  determine  their 
relationship  to  one  another  and  to  the  examples  here  described.  The  figures  given 
l)y  Defrance  do  not  enable  us  to  form  a  satisfactory  idea  of  the  characters  of  the 
species;  in  his  original  account  (1820)  he  gave  "  He  d'Aix"  as  the  locality,  but  in 
his  later  remarks  (1824)  he  states  that  the  specimens  came  from  the  department 
of  Le  Manche. 

The    Senonian   specimens    figured    by   d'Orbigny'  as   (/.   iii-iri(loiiJcs  (noii    G. 

'  From  posterior  end  of  liiu^-e-liuo  to  opposite  margin  of  valve. 
-  From  umbo  to  posterior  extremity. 

*  'Ceutralb.  fiir  Miu.,'  etc.  (1902),  p.  G15. 

*  Sowerby  (18-20),  Goldfuss  (183(J),  Iteuss  (184(j),  Midler  (1847),  d'Orbiguy  (1847),  .\ltli  (18,50), 
Zittel  (1866),  Favre  (1869),  StoUczka  (1871),  Geiuitz  (1873),  Brauus  (1876),  Fritscb  (1877-93), 
Niitling  (1885),  Griepeukerl  (1889),  Holzapfel  (1889),  Liiudgreu  (1894),  Vogel  (1895),  Midler  (1898), 
G.  oblonga,  Bohm  (1885). 

5  'Diet.  Sci.  nat.,'  vol.  xviii  (1820),  p.  503;  vol.  xxxii  (1824),  p.  316,  pi.  Ixxxvi,  fig.  6. 

«  'Pal.  Fran^.  Terr.  Crct.,'  vol.  iii  (1846),  p.  489,  pi.  cccxcvii,  fig.  2  (aud  perhaps  fig.  1).  Prof. 
M.  Boule  informs  me  that  the  original  of  fig.  1  cannot  be  found  in  the  d'Orbiguy  collection,  aud  that 
the  original  of  fig.  2  comes  from  Valogues  (Manche). 


PERXA.  87 

aviculoides,  Sowerby)  were  afterwards '  referred  by  that  writer  to  G.  sohnoides, 
Defrance,  whilst  the  Cenomanian  forms  from  Le  Mans,  also  figured  as  G.  solenoides, 
were  named ''  G.  subaviculoides. 

The  examples  of  G.  solenoides  from  the  Senonian  of  Aachen  figured  hy  Ilolzapfcl  ^ 
differ  from  our  specimens  of  G.  Forhesiana  in  the  greater  height  of  the  posterior 
ear  and  in  its  indistinct  separation  from  the  rest  of  the  valve,  also  in  having  a  larger 
apical  angle. 

Ti/pes. — Two  of  the  specimens  figured  as  G.  solenoides  by  Sowerby  (figs.  2,  3) 
are  in  the  British  Museum  and  came  from  Shanklin.  Another  specimen  figured  by 
Sowerby  (fig.  1),  from  the  Upper  Greensand  of  Lyme  Regis,  is  in  the  Museum  of 
the  Geological  Society  of  London  (No.  1555),  but  is  not  recorded  in  Mr.  Blake's 
"  List  of  Types."  D'Orbigny's  type  of  G.  Forhesiana  apparently  came  from  the 
Crackers  of  Atherfield,  but  Professor  Boule  informs  me  that  the  specimen  cannot 
now  be  found  in  the  d'Orbigny  Collection. 

Distribution. — Ferna-hed,  Atherfield  Clay,  and  Crackers  of  Atherfield.  Fitton's 
Bed  3G  of  Blackofang.  Ferruginous  Sands  of  Shanklin.  Atherfield  Beds  of  Peas- 
marsh.     Hythe  Beds  of  Pulborough.     Sandgate  Beds  of  I'arham  Park. 

Gault  (zones  iii  to  vii,  and  viii)  of  Folkestone.  Zone  of  Ilnjilites  interraptus  of 
Okeford  Fitzpaine  (Dorset).  Cambridge  Greensand  (dei'ived).  Upper  Greensand 
of  Blackdown. 


Genus — Perna,  J.  G.  Bnujuiere,   17S0. 
('Encyc.  Method.,  Vers,'  vol.  i,  p.  xiii.) 

Peuna  Muli-eti,  Deshayes,   1842.     Text-figure  15. 

1842.     Perna  MuLLETi,  Des/iayes  iu  A.  Leymerie.     Mi-m.  Soc.  gt'ol.  de  France,  ser. 

2,  vol.  V,   p.  8,  pi.  xi,  figs. 
1-3. 
184.5.         —  —       E.  Forbes.     Quart.  Jouru.  Geol.  Soc,  vol.  i,  p.  246,  pi.  i, 

figs.  1 — 4. 
1846.         —      Uvi.i.Eru.  A.  d'Orbigny.     Pal.  Fran?.  Terr.  Crut.,  vol.  iii,  p.  4%,  pis. 

cccc,  cccci,  figs.  1 — 3. 
1848.         —      MuLLETi,   C.  L.  Korli.     Paloeontograpliica,  vol.  i,  p.  171,  pi.  xxiv, 

fit's.  14 — 17. 


'  '  Prodr.  de  Pal.,'  vol.  ii,  1850,  p.  250. 

2  Ibid,  vol.  iii  (1852),  p.  72  (index)  ;  d'Orbigny.  'Pal.  Fran?.  Terr.  CrJt.,'  vol.  iii  (1846),  p.  489, 
pi.  cccxcvii,  figs.  3,  4,  5.  Prof.  Boule  informs  me  that  these  ai-e  from  lie  Mans,  an.l  aiv  n.)«  in  the 
d'Orbigny  collection. 

'  •  Mollusk.  Aachen.  Kreide'  (1889),  p.  223,  pi.  xxiv,  figs.  11,  12. 


88  CRETACEOUS   LAMELLTBRANCHIA. 

1850.     Perna  Muletii,  A.  d'Orh'ujny.     Pnxlr.  <1p  Pal.,  vol.  ii,  p.  82. 

1854.  —       MuLLETi,  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  179. 

1855.  —       Mdletii,  G.  Colteau.     Moll.  Foss.  de  I'Yonne,  p.  106. 

1869.  MuLLETi,  F.  J.  Piciet  and  G.  Campiclie.    Foss.  Terr.  Crct.  Ste.  Croix 

(Mater.  Pal.  Suisse,  ser. 
5),  p.  97,  i-l.  clviii. 

—  -  —      YoB,B^ST,  Pictel  avd  Camjiirhe.     ll)i(l.,  p.  H9,  pi.  clix. 

1871.     Medina  Muli.eti,  F.  Stoliczka.     Palaeont.  Indica,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  400. 

1883.  Perna  Mulleti,   W.  Keepimj.      Foss.  etc.,    Neoc.  Upware   aii<l    Uritkhill, 

p.  160. 

1884.  —  —  O.Weerth.     Die  Fauna  des  Neoeom.  im  Teutoburg.  Wald. 

(Palajont.  Abhandl.,  vol.  ii),  p.  49. 
1886.         —      (Mulletia)    Mult.eti,    P.   Fisrher.      Manuel   de   Conch.,   p.   956, 

fig.  725. 

1895.  —      MuLLETT,  F.  Vogel.     Hollaudisch.  Kreide,  \\  55. 

—  —  —         G.    Maan.     Zeitschr.    der   deutscli.    geol.    Gesellscli.,    vol. 

xlvii.  p.  267. 

1896.  —         A.  WoUemann.     Ibid.,  vol.  xlviii,  p.  843. 

1900.         —  —  —  Die  Biv.  u.  Gastrop.  d.  deutscli.  u.  liol- 

liind.  Neocoms  (Abhandl.  d.  k.  prens- 
sich.  geol.  Land.,  N.  F.,  pt.  31),  p.  60. 

Description. — Shell  largo,  thick,  compressed,  more  or  less  fitiadrilatcral,  with 
unequal  angles.  Hinge-line  long.  Unibones  almost  terminal.  Anterior  part  of 
the  shell  sharply  bent,  and  more  or  less  nearly  perpendicular  to  the  plane  of  the 
two  valves  ;  anterior  marginal  part  more  or  less  deeply  concave.  From  the  umbo 
start  two  strong,  broad,  rounded  folds  ;  the  anterior  of  these  is  near  the  anterior 
margin  and  curves  anteriorly,  its  extremity  forming  the  aiitero-ventral  angle ;  the 
posterior  fold  at  first  curves  ventrally  and  afterwards  posteriorly,  and  its  termina- 
tion forms  the  postero-ventral  angle.  The  part  of  the  shell  behind  the  posterior 
fold  is  compressed  and  flattened  and  produced  into  a  wing  of  varying  length. 
The  junction  of  the  two  valves  is  sinuous,  the  anterior,  the  ventral,  and  the 
posterior  margins  (between  the  angles)  being  concave  on  the  right  valve  and 
convex  on  the  left. 

The  shell  is  ornamented  with  distinct  growth  ridges  which  bend  ventrally  in 
passing  over  the  folds  and  form  a  semicircular  or  semi-oval  curve  near  the 
hinge-line. 

Measurements  .- 

(1)  (2)  (3) 

Length  of  hingc-linc        .  .128         .  120         .  95  nun. 

Height  (from  umbo  to  postero- 
ventral  angle).         .         .     114         .         135         .         130    „ 

(1 — 3)  Pern«-bed,  Atherfield. 


I'ERXA. 


89 


Affinities. — The  forms  foiuul  in  the  Lower  Greensand  of  England  which  had 
been  referred  to  Perna  Mullcti  by  earlier  writers  were  regarded  as  distinct  by 
Pictet  and  Campiche,  and  were  named  by  them  Perna  Forbesi.  They  considered 
that  the  latter  were  distinguished  by  the  more  prominent  folds,  the  shorter  and 
more  deeply  concave  anterior  mai'gin,  and  the  longer  posterior  wing.  An 
examination  of  a  number  of  specimens  shows  that  these  characters  are  variable, 
and  I  am  led  to  agree  with  Wollemann  in  thinking  that  the  forms  described  by 
Pictet  and  Campiche  cannot  be  regarded  as  more  than  varieties  of  a  variable 
species. 


Fio.  lo.— Perna  Midleti,  Desliayes.  Lower  Greensand  (Perna-hed),  Sandown.  Sedgwick  Museum.  Left 
valve  X  }.  (The  posterior  win},'  is  broken.  Forbes  gives  a  figure  of  a  specimen  in  which  the  wing  is 
perfectly  preserved.) 

Perna  Midleti  is  tlie  type  of  Fischer's  section  Mullclia. 

Ti/pe. — From  the  Neocomian  of  Veudeuvre.  I  have  not  seen  the  specimens 
figured  by  Forbes. 

Distribution.— Perna-hed  of  Athcrfield  and  Sandown.  Atherfiekl  Beds  of 
Haslemere,  Peasmarsh,  Sbalford,  Redhill,  Sevenoaks,  and  Hythe.  llythe  Beds 
of  Hythe  {fide  Topley).  Lower  Greensand  of  Potton  and  Upware.  Tcalby 
Limestone  (zone  of  B.  bninscicensis)  of  North  Willingham.  Speeton  Clay  of 
S pee ton. 


12 


90 


CKETAt!E()LiS    LAMELUBRAXfTITA. 


Pehna  HicoRDiiANA,  iV Orb i(j hi/,  IS-l'O.     Text-figures  lG-1 8. 


184(J. 

1850. 
1854. 
1855. 
1858. 


18(iy.         — 


181)9. 
1883. 

1900. 


Perna  Kicoedeana,  a.  d'Orhiijmj.     Pal.  Fiiiui;.  Terr.  Crct.,  vol.  iii,  p.  VJ-i, 

pi.  cccxcix,  figs.  1 — 3. 

—  —  d'Orbigny.     Prodr.  de  Pal.,  vol.  ii,  j).  82. 

—  —J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  179. 

—  G.  Coiteau.     Moll.  Foss.  do  I'Youue,  p.  107. 

—  —  F.  J.  Pictet  and  E.  Benevier.  Foss.  Terr.  Aptien  (Mater. 

Pal.  Suisse,  ser.  1),  p.  125. 

—  F.  J.  Pictut  and  G.  Campiche.     Foss.  Terr.  Crct.  Ste. 

Croix  (Mater.  Pal.  Suisse,  ser. 
5),  p.  93,  pi.  clvii,  fig.  1. 

FiTTONi,  Pictet  and  Camjiiche.     Ibid.,  p.  95,  pi.  clvii,  fig.  2. 
RicouDiANA,  W.  Keeping.     Foss.,  etc.,  Neoc.  Upware  and  BrickJiill, 

p.  150. 
RicoEDEANA,  A.  WoUevHinn.     Die  Biv.  u.  Gastrop.  d.  deutsch.  u. 

hoUiiud.  Neocoms  (Abliaudl.  d.  k. 

preussisch.  geol.  Land.,  N.  F.,  pt. 

31),  p.  61. 


Fio.  10. —  Pcma  Rifordcana,  trOrbigny.     Lower  Cireousaml  (Penta-bud),  AtliL'i-fiuld.     BIiiSL'iim  of  Practical 
Geology,  No.  12351.     Left  valve,      x  J. 


Descriftion. — Shell  large,  tliick,  sub-quadrate,  compressed;  left  valve  more 
convex  than  the  riglit.  Posterior  margin  sligiitly  convex  or  nearly  straight  and 
forniiiig  with  the  hingo-line  an   angle   which   is   rather  greater  than  a  right-angle. 


PEHXA. 


91 


Ventral  margin  curved  reo•ular]3^  Dorsal  part  of  anterior  margin  concave. 
Valves  moderately  convex  near  the  anterior  margin,  but  flattened  clscwliere. 
Dorsal  half  or  more  of  the  anterior  marginal  parts  concave  and  depressed.  Umbones 
sharp,  close  together,  projecting  beyond  the  rest  of  the  anterior  margin  of  the 
valves. 

Surface  with  growtli-lamella)  at  more  or  less  regular  intervals. 

Mensiiremenf.'^  ; 

(1)  (2)  (3) 

105         .  91  .  75  mm. 

1 1<»       .       i(i<;       .       kh    „ 

(1—3)  Pernn-hcd,  AtlievfieW. 


Length  of  liinge 
Height  of  valve 


V- 


Fill.  17. — Perna  Ricordeana,  (VOrbiijny-     Lower  Greensand  (Pcrno-bed),  Atlioifiold.     Seilfovick  Museum. 
Eight  valve  and  anterior  view  of  both  valves,      x  J. 


Affijiities. — Examples  of  this  species  from  the  Lower  Greensand  of  the  Isle  of 
Wight  were  regarded  by  Pictet  and  Campiche  as  distinct  from  P.  li'icordcaim  and 
were  described  as  Perna  Fittoni.  According  to  those  writers  the  former  is 
distinguished  from  the  latter  chiefly  by  the  wide  separation  of  the  umbones ;  this 
separation,  however,  seems  to  me  to  be  due  to  the  thickening  of  the  valves  in  old 
age,  such  as  may  be  seen  not  infrequently  in  GerviUia  and  other  allied  forms. 
The  postero-dorsal  angle  of  the  valve,  according  to  d'Orbigny's  figure,  appears  to 
be  rather  smaller  in  P.  EkonJmna  than  in  P.  Fittoni,  but  the  difference  is  not 
great,  and  moreover,  the  outline  of  the  shell  and  the  size  of  this  angle  vary  in 
different  specimens  of  P.  Fittoni.  /'.  German i,  Pictet  and  Campiche,  is  very 
closely  allied  to  P.  Ricordeana. 


92 


CRETACKOrS    LAMET>LI  liHAXrHIA. 


Types. — From  tlic  Neocomian  of  Soignelay,  near  Auxerre.  The  type  of 
P.  Fittoni  is  from  the  Pen^a -bed  of  the  Isle  of  Wiglit. 

Distribution. — Lower  Grecnsand  (Pcj-)m-bed)  of  Atherfield.  Tcalby  Liiiu'stone 
(zone  of  Bdemnites  hrunsvicensis)  of  Nortli  AViningliam. 


Fio.  18.—Pcrna  Ricordeana,  d'Orbigny.      Tcalby   Limestone,  North   Willingham.      Sedgwick  Museum. 
Loft  valve,     x  J. 


Perna  Rauliniana,  (VOrUgmj,  1846.     Plate  XII,  figs.  6,  la,  h,  8,  9. 

1846.     Pkena  Rauliniana,  A.  d'Orhujny.     Pal.  Pran9.  Terr.  Crct.,  vol.  iii,  p.  497, 

pi.  cccci,  figs.  4,  5. 
1850.         —  —  d'Orbigny.     Prodr.  de  Pal.,  vol.  ii,  p.  138. 

1852.         —  —  F.  J.  PicM  and  W.  Bona:     Moll.  Foss.  Grcs  verts  de 

Geneve,  p.  497,  pi.  xli,  fig.  4. 

1854.  —  —  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  179. 

1855.  —  ~  G.  Cottcav.     Moll.  Foss.  de  I'Youne,  p.  107. 

1869.         —  —  F.  J.  Pictet  and  G.  Campichc.     Foss.  Terr.  Crtt.  Ste. 

Croix  (Mater.  Pal.  Suisse,  ser. 
5),  ]).  100,  pi.  clx,  figs.  1,  2. 

Description. — Shell  of  moderate  convexity,  valves  nearly  equal,  compressed 
posteriorly,  snb-rhomboidal,  oblique,  much  higher  than  long;  postero-ventral 
margin  rounded,  anterior  margin  slightly  concave,  posterior  margin  slightly  convex, 


(3) 

(4) 

(5) 

24 

23 

1  1  111111. 

49       . 

40 

i)o 

PERNA.  93 

forming  an  olituse  angle  with  the  hinge-line.     IJmltonnl  jinrtion  angular.      Apical 
angle  small.     Surface  with  growth-lines. 
Measurements  -.^ 

(1)  (2) 

Length        .         .       35       .       34       . 
Height         .  .       73       .       G9       . 

(1 — 3,  5)  Cambridge  Greonsand. 

(4)  Lower  G-ault,  Folkestone. 

Affinities'. — This  species  is  closely  allied  to  P.  Bicordeana  (see  above),  but 
appeal's  to  differ  (1)  in  being  relatively  shorter  and  higher;  (2)  in  its  more  obtuse 
postero-dorsal  angle ;  (3)  in  the  less  prominent  uinbones ;  (4)  in  the  anterior 
marginal  parts  (near  the  byssal  opening)  being  less  depressed ;  (5)  in  the  smaller 
size  of  the  shell. 

Bemarl-s. — This  species  occurs  commonly  in  the  Cambridge  Greensand  in  the 
form  of  internnl  casts;  these  differ  in  outline  fi-om  specimens  with  the  shell  pre- 
served on  account  of  the  fact  that  the  postero-dorsal  part  is  missing — probably 
owing  to  the  two  valves  being  in  contact  or  almost  in  contact  at  this  part.  Even 
when  the  shell  is  preserved,  as  in  specimens  from  the  (xault,  some  portion  of  the 
postero-dorsal  margin  is  frequently  missing. 

Types. — From  the  Albian  of  Avocourt  (Meuse)  and  Escragnolles. 

Bistrihution. — Cambridge  Greensand  (derived,  intornal  casts).  Lower  Gault  of 
Folkestone. 


Perna  oblonga, /S'ee^ey,  18GL     Text-figure  10  a. 

1861.     Perna  oblonoa,  H.  G.  Seeley.     Ann.  Mag.  Nat.  Hist.,  ser.  3,  vol.  vii,  p.  121, 

pi.  vi,  fig.  6. 

Remarks. — This  species  is  known  only  from  internal  casts,  and  apparently 
differs  from  P.  Batdiniana  in  having  a  larger  apical  angle  and  in  the  smaller  angle 
formed  by  the  hinge-line  and  the  posterior  margin.  Some  of  the  specimens,  how- 
ever, agree  very  closely  with  the  figure  of  a  cast  of  P.  liauliniana  given  by  Pictet 
and  Campiche  (pi.  clx,  fig.  2). 

Seeley  compared  P.  ohlonga  with  P.  suhspathulata,  Reuss,=  and  P.  lanccolata, 
Geinitz  (see  below).  It  is  distinguished  from  the  former  by  its  relatively  greater 
height,  and  from  the  latter  by  its  larger  apical  angle. 

1  The  height  in  this  ease  is  measured  from  the  umbo  to  the  postero-ventral  margin,  and  the 
length  is  taken  at  right  angles  to  tlie  height. 

-  •  Die  Verstein.  der  l.i.lim.  Kreideforniat."  pt.  ii  (184*;).  {>•  24,  pi.    xxxii.  figs.  IC.  17. 


94 


CRETACEOUS    LAMELLTBRANGHIA. 


Rounded  depressions  wliicli  are  found  commonly  on  the  casts  of  this  and  some 
other  species  of  /'')•//*'  fi'oin  tlie  Cambridge  Greensand  are  regarded  by  Seeley  as 
evidence  of  the  occurrence  of  pearls. 

A  specimen  from  the  Gault  (Plate  XII,  fig.  10)  resembles  P.  oJiJoinja,  but  is 
more  convex  between  the  umbo  and  the  ])ostero- ventral  exti-emity. 

Type. — In  the  Sedgwick  Museum. 

DiMrihuilon. — Cambridge  Greensand  (derived). 


cnm.     Cainbriclf^e  Groonsanil  (derived).     Internal   casts.     Sedgwick   Museum.     Natm-al  size, 
Eg.  E. — A.  Pcnia  oblonga,  Soeley.     The  Type. — B,  c,  Perna,  sp.  (referred  to  I',  lanccolata,  Geinitz, 


Fict.  19. -Pf 

except  fig  ...  . .  .     . 

by  Seeley).— D,  Perna  semielliiitira,  Seeley.     The  Type.— E,  Pema,  sp.  (regarded  by  Seeley  as  a  variety 
of  P.  lanceolata,  Geinitz)   x   'i. — p,  Penia,  sp.  (referred  to  P.  sxibspathulala,  Keuss,  by  Seeley). 


Perna  sumiet.uptica,  St'clci/,  18C1.     Text-figure  19  d. 

1861 .     Perna  semielliptica,  H.  G.  Seehy.     Ann.  Mag.  Nat.  Hist.,  ser.  3,  vol.  vii, 

p.  121,  pi.  vi,  fig.  7. 

Bemarlcs. — This  is  distinguished  from  P.  Rnuliniana  (p.  02)  by  its  relatively 
greater  length,  larger  apical  angle,  and  more  rounded  outline. 


PERN  A.  95 


easurements  : 

(1)                                        (2) 

(3) 

Length 

. 

58             .             46             . 

32  mm 

Height 

, 

87             .            70            . 

47     „ 

(1 

—3)  Cambridge  Greeusand. 

Ti/jie. — From  the  Cambridge  Greensand.    In  the  Sedgwick  Museum,  Cambridge. 
Distrilinf ion— Cambridge  Greensand  (derived,  internal  casts). 


Perna,  sp.     Text-figures  19,  a  c. 

1861.     Perna  lanceolata,  H.  G.  Seeley.     Auu.  Mag.  Nat.  Hist.,  ser.  3,  vol.  vii, 

p.  122. 

Remarks. — This  species  (figs.  19  i;,  c)  was  referred  l)y  Professor  Seeley  to 
Perna  lanceolata,  Geiuitz,'  and  it  presents  a  general  resemblance  to  the  examples 
figured  by  Reuss  and  by  d'Orbigny,  but  is  less  oblique.  No  satisfactory  com- 
parison, however,  can  be  made,  since  the  specimens  from  the  Cambridge 
Greensand  are  in  the  form  of  internal  casts. 

Some  examples  (fig.  19  e)  were  named  Perna  lanceolata,  var.,  by  Seeley;  they 
differ  from  Geinitz's  species  in  the  postero-ventral  part  being  more  produced  and 
less  rounded,  so  that  the  outline  of  the  valve  becomes  more  distinctly  quadrate.  By 
this  quadrilateral  outline  they  are  distinguished  from  P.  IianUniana. 

Didrihution. — Cambridge  Greensand  (derived,  internal  casts).  ^ 


Perna,  sp.     Text-figure  19  f. 

1861.     Perna  subspathulata,  H.  G.  Seeley.     Auu.  Mag.  Nat.  Hist.,  ser.  3,  vol. 

vii,  p.  124. 

Remarks. — Internal  casts  wei*e  regarded  by  Professor  Seeley  as  examples  of 
r.  snhspathnlata,  Reuss,^  but  they  appear  to  dift'er  from  the  latter  in  their 
greater  convexity.     The  height  is  less  and  the  length  greater  than  in  P.  ohlomja. 

Distribution. — Cambridge  Greensand  (derived).^ 

>  '  Das  Elbthalgeb.  iu  Sacbseu,'  pt.  i  (1873),  p.  210,  pi.  xlvi,  fig.  8.  References  to  other  figures 
ai-e  given  by  Geinitz. 

*  '  Die  Versteiu.  der  bohm.  Kreidofonnat.,'  pt.  ii  (1846),  p.  24,  pi.  xxxii,  figs.  16,  17. 

3  Avicula  cuneala,  Seeley,  may  bo  a  Penm.  Perna  lissa,  P.  plana,  and  P.  transverta,  Seeley. 
apjjear  to  be  Inocerami.  All  four  come  from  the  Eed  Limestone  of  Huustautou.  Seeley, '  Ann.  Mag. 
Nat.  Hist.,'  ser.  3,  vol.  xiv  (1864),  p.  277,  and  vol.  xvii  (1866),  pp.  178,  170. 


96  CRKTACEOUS  LA.M  KLLI  BRAXCHIA. 

Familij—mNmDJE,  Giriy. 
Gcnns — Pinna,  LimnvuK,  1758. 
('Syst.  Nat.,'ed.  10.  p.  707.) 
Pinna  Riuhnaldina,  d'Orliiijinj,  184-1-,     Plato  XII,  figs.  11-15;  Plate  XIII,  fig.  1. 

1839.     Pinna  kugosa,  F.  A.  Biimer.     Die  Versteiu.  d.  uord-deutsch.  Oolith.-geb. 

Nachtrag.,  p.  32,  pi.  xviii,  fig.  37  (uou 
rvgosa,  Scblotlieim). 

1841.         —  —       F.  A.  Burner.     Die  Verstein.  d.  nord-deutscb.  Kreidegeb., 

p.  65. 

1844.  —      RoBiNALDiNA,  A.  d'OrUgnij.     Pal.  Frau9.  Terr.  Cre't.,  vol.  iii,  p.  251, 

pi.  eccxxx,  figs.  1-3. 

1845.  —      KESTiTUTA,  E.  Forbes.     Quart.  Journ.  Geol.  Soc,  vol.  i,  p.  248. 
1850.        —     RoBiNALDiNA,  A.  d'0rbi(j7iy.     Prodr.  de  Pal.,  vol.  ii,  p.  80. 

—  —      SUBBOGOSA,  d'Orhi(jny.     Ibid.,  p.  80. 

1854.  —      suLciFEBA,  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  180. 

1855.  —      ROBINALDINA,  G.  Cotteau.     Moll.  Foss.  de  rYonne,  p.  89. 

1858.         —  —  F.  J.   Pictet  and  E.  JRenevier.     Foss.   Terr.   Aptien 

(Mater. Pal.  Suisse, 
ser.  1),  p.  117, 
pi.  xvi,  fig.  5. 

—  —  —  J.ViUanova-y-Piera.     Mem.  geog.-agric.  de  Castelluu, 

pi.  lii,  fig.  17. 
1865.         —  —  //.  Cuquand.     Mon.  Aptien  de  I'Espagne,  p.  143. 

1867.         —  —  F.  J.  Pictet  and  G.  Cam.piche.     Foss.  Terr.  Crct.  Ste. 

Croix    (Mater.    Pal. 
Suisse,  ser.  4),  p.  532, 
pi.  exxxix,  figs.  3-6. 
?  1882.         —  —  P.  de  Loriol.     Gault  de  Cosne,  p.  82,  pi.  x,  figs.  3-5. 

1883.  —  —  W.  Keejiing.     Foss.,  etc.,  Neoc.  Upware  and  Brick- 

biU,  p.  110. 

1884.  —  —  0.  Weerth.     Die  Fauna  des  Neoconi.  im  Toutoburg. 

Walde  (Palceout.  Abbaudl.,  vol.  ii) ,  p.  48. 
?  1892.        —  —  0.  Behrendsen.    Zeitscbr.  der  deutscb.  geol.  Gesellscb., 

vol.  xliv,  p.  25. 
?  1895.         —  —  F.  Voijcl.     HoUiiudiscb.  Kreide,  p.  55. 

1896.         —  —  A.Wollemanri.    Zeitscbr.  der  deutscb.  geol.  Gesellscb., 

vol.  xlviii,  p.  845. 

1899.  —  —  G.  Maas.      Zeitscbr.    der  deutscb.    geol.    Gesellscb., 

vol.  U,  p.  248. 

1900.  —  —  A.  Wollemann.     Die  Biv.  u.  Gastrop.  d.  deut.scb.  u. 

bolland.  Neocoms  (Abliandl.  d. 
k.  preussiscb.  geol.  Laud.,  N.  F., 
pt.  31),  p.  70. 


Ipalxontoovaphical  Socict\?,   1900. 


A    MONOd  T{  A  p  ir 


CRETACEOUS    LAMELLIBIIANGHIA 


ENGLAND. 


BY 


HENUY  WOODS,  M.A. 

UNIVERSITY    LECTURER    IN    PAL.EOZOOI.OGT,    CAM8RID0E. 


VOL.  TT.     PART  III. 

PINNIDiE     ASTAETIDiE,    CAllDITIDJ:,    CRASSATELLITIDiE. 

AND    CYPEINID.E. 

Paoes  97—132;    Plates  XII— XIX. 


LONDON: 
PKINTED     FOK     THE     PA  L^ONTOU  i;  A  P  Jl  IC  A  L     SOCIETY. 


J'UINTKl)    1;Y    AllLAKD    AND    SON,    LONDON    AND    DORKINC. 


PINNA.  97 

y  1888.     Pinna  Eobinaldina,  P.  Choffaf.    Stratigr.  et  Paleont.  d'Angola  (Mi'm.  Soc. 

pliys.  et  cVliist.  uat.  do  Goul-vc,  vol.  xxx, 
No.  2),  p.  8(j,  pi.  V,  figs.  4,  5. 

?  1903.         —  _  0.  Burckhardt.     Jura  u.  Kreidef.  d.  Cordillere  (Palte- 

outographica,  vol.  1),  p.  7ft,  pi.  xv, 
figs.  C,  7. 

V  100.5.         —     cf.  Eobinaldina,  E.  Harhort.     Fauna    d.   Schaumburg-Lipije'sclien 

Kreidemulde  (Abhandl.  d.  k.  preus- 
sisch.  gcol.  Landesanst.,  N.P.,  Heft 
4.5),  p.  47,  pi.  V,  fig.  .5  ;  pi.  vii, 
figs.  2,  3. 

Descrijition. — Shell  straight,  much  elongated;  pyramidal,  slightly  compressed ; 
margins  nearly  straight;  section  sub-qnadrangnlar. 

Each  valve  is  divided  into  two  parts,  which  meet  at  an  angle.  The  dorsal  part 
is  smaller  and  more  flattened  than  the  ventral  part,  and  is  ornamented  with  from 
G  to  8  or  more  ribs,  which  are  narrow,  strong,  and  nearly  equi-distant.  The  ribs 
are  separated  by  broad,  shallow,  rounded  depressions ;  both  depres.sions  and  ribs 
are  crossed  by  very  fine,  somewhat  irregular,  concentric  ridges,  which  sometimes 
give  a  slightly  serrated  appearance  to  the  ribs.  The  ventral  part  of  each  valve  is 
moderately  convex,  and  its  dorsal  portion  is  ornamented  with  from  5  to  7  radial 
ribs  similar  to  those  on  the  dorsal  part  of  the  valve,  but  decreasing  in  size  ventrally; 
the  last  one  or  two  of  these  ribs  sometimes  become  irregular  and  discontinuous. 
Tliese  radial  ribs  and  their  interspaces  are  crossed  by  fine  concentric  ridges.  The 
ventral  portion  of  the  ventral  part  of  the  valve  is  ornamented  with  strong  growth- 
ridges  or  folds,  which  curve  rapidly  in  the  direction  of  the  unil)o,  and  form  an 
acute  angle  where  they  meet  the  ribs. 

Measurements : 

(1)  (2) 

Length         .       135         .         94  mm. 

Height  .     •    49         .         41     „ 

(1)  Perna-hvA,  Atherfield. 

(2)  Crioceras-hcA,  Whale  Chine. 

Afinifief!. — The  figure  of  P.  (jracilis,  Phillips,'  is  not  .sufficiently  good  to  enable 
one  to  form  a  satisfactory  idea  of  the  character  of  the  species,  and  the  type  cannot 
now  be  found.  But  other  specimens  from  Speeton,  although  very  imperfectly 
preserved,  are  sufficient  to  suggest  that  P.  (jracilis  is  probably  identical  with  P. 
Rohinalilina. 

It  is  suggested  by  Pictet  and  Campiche  that  P.  tetrngona,  Sowerby,-  from  the 

>  '  Geol.  Torks.'  (182ft).  P-  122,  pi.  ii,  fig.  22. 

2  'Min.  Conch.,'  vol.  iv  (1821),  p.  9,  pi.  cccxiii,  fig.  1;  Morris,  'Cat.  Brit.  Foss.,' ed.  2  (1854), 
p.  180;  P.  subieirMjona,  d'Orbigny,  '  Prodr.  de  Pal.,'  vol.  ii  (1850),  p.  165;  Pletet  and  Campiche. 
'Terr.  Crct.  Ste.  Croix'  (18(37),  p.  587;  nou  P.  tdraijuna,  Brocchi,  1814. 

13 


98  CRETACEOUS   LAMELLIBRANCHTA. 

Uppei'  Greensand  of  Devizes,  is  probably  identical  with  P.  Ilnhinnldina,  The 
specimens  from  Devizes  agree  with  those  found  at  Blackdown  in  having  the  folds 
on  the  ventral  part  of  the  valve  rather  more  strongly  marked  than  in  P.  Robhialdina 
from  the  Lower  Greensand.  In  other  respects  the  Upper  Greensand  form  does 
not  appear  to  differ  from  P.  RoUnaltUna ,  and  may  be  regarded  as  a  variety  of  it, 
P.  Eohinaldina  var.  tetragotia,  Sowerby. 

P.  Beijncsi,  Hebert  and  Mnnier-Clialmas,'  is  similar  to  P.  Iiohiunhliiia,  but 
apparently  differs  in  that  the  ribs  on  the  ventral  part  of  the  shell  are  all  smaller 
than  those  on  the  dorsal  part,  and  do  not  diminish  gradually  in  size. 

P.  cretacea  (Schlotheim)-  is  closely  related  to  1'.  Bobinaldina,  but  appears 
to  be  distinguished  (1)  by  tlie  ribs  covering  a  larger  proportion  of  the  ventral 
part  of  the  shell  and  being  of  nearly  uniform  size,  (2)  by  the  growth-lines  on 
the  ventral  part  being  more  nearly  straight,  (3)  by  the  shell  being  usually  more 
elongate. 

Bemarls. — The  specimens  of  Pin  mi  fouiul  in  the  Gault  of  Folkestone  and  Black 
Ven  have  usually  been  named  P.  tetrar/oua.  Their  mode  of  preservation  is  more 
or  less  unsatisfactory,  OAving  to  crushing  and  to  the  absence  of  some  of  the  outer 
layers  of  the  shell,  but  after  a  close  comparison  with  examples  of  7^.  Bohinaldina 
from  the  Lower  Greensand  I  am  unable  to  see  any  reason  for  regarding  the  former 
as  specifically  distinct  from  the  latter. 

Pictet  and  Campiche  thought  that  the  examples  from  Blackdown  were  referable 
to  P.  Eohinaldina,  differing  only  in  having  the  folds  on  the  ventral  part  of  the  shell 
rather  more  strongly  marked. 

The  specimens  from  the  Lower  Greensand  of  the  Isle  of  Wight  agree  well  with 
the  figures  given  by  Pictet  and  Renevier  and  liy  Pictet  and  Campiche.  The 
luimber  of  ribs  varies  considerably,  and  in  young  specimens  the  apical  angle  is 
smaller  than  in  oldei'  examples. 

A  specimen  from  the  Upper  Greensand.of  Ventnor,  which  lias  been  referred'^ 
to  P.  Eeynesi,  Hebert  and  Munier-Chaltnas,  is  probably  a  crushed  example  of 
P.  Eobinaldina. 

Tijpe. — The  type  of  P.  riigosa-  came  from  the  Hils-conglomerate  of  Osterwald. 
The  type  of  P.  tcfiru/mia,  Sowerby,  came  from  the  Upper  Gi'eensand  of  Devizes 
and  is  now  in  the  British  Museum. 

Distribution. — Perna-heA,  Crackers,  and  Fitton's  Beds  16  and  38,  of  Atherfield. 

Ferruginous  Sands  of  Shanklin.      Atherfield  Beds  of  Redhill,  Reigate.     Sandgate 

Beds  of   Parham  Park.      Lower  Greensand  of  Brickhill.     PSpeeton  Clay   (zone 

of    Ihlemnites  hrunHvicenais)  of  Speeton.     Gault  of  Folkestone  and    Black   Ven. 

'  'Aim.  Sciences  gt'ol.,'  vol.  vi  (1875),  p.  118,  pi.  v,  fig.  10. 

-  Geinitz,  'Das  Elbthalgeb.'  (Palceontographica,  vol.  xx,  pt.  2,  1873),  p.  54,  pi.  xiv,  figs.  2,  8. 

■*  Jukes-Browne,  'Cret.  Eocks  of  Britain,'  vol.  i  (1900),  p.  470. 


PINNA.  99 

Upper  Greeiisand   (zone   of    Schla;nhachia   rodrata)  of   Blackdown,  Devizes,  and 
Ventnor.^ 


Pinna,  sp.     Plate  XIII,  figs.  2,  3. 

Some  specimens  of  Pinna  found  in  the  Gault  of  Folkestone  differ  from 
P.  liohhidhUna  in  having  smaller  and  more  numerous  ribs,  wbicli  arc  crossed  at 
regular  intervals  by  narrow  concentric  ridges. 


Pinna  tegdlata,  Etherichje,  1881. 

1881.  Pinna  tegulata,  R.  Etheridge,  ia  Penning  and  JuJces-Browne's  Geol.  Cam- 
bridge (Mem.  Geol.  Survey),  p.  142,  pi.  i, 
fig.  2. 

Bemarlcs. — This  species  is  known  only  by  the  type  and  a  few  fragmentary 
specimens.  The  tj^pe  shows  the  interior  of  a  right  valve.  The  ornamentation 
appears  to  be  similar  to  the  form  from  the  Gault  described  above.  On  the  dorsal 
half  of  the  valve  there  are  about  18  narrow  ribs,  which  are  crossed  at  regular 
intervals  by  concentric  ridges,  giving  rise  to  a  fimbriated  appearance.  About  8 
similar  ribs  are  found  on  the  dorsal  part  of  the  ventral  half  of  the  valve,  below 
which  are  strongly  curved  growth-ridges. 

Typo. — In  the  Sedgwick  Museum,  Cambridge. 

Distribution. — Totternhoe  Stone  (zone  of  Hulastcv  suhgluhusua)  of  Eurwell. 


Pinna  decussata,  GohJfnss,  18o7.     Plate  XIII,  figs,  -ia-c,  5,  G.     Plate  XIV,  fig.  1. 

1833.     Pinna  sulcata,  <S'.  WoodirariL     Geol.  Norfolk,  p.  4:7,  pi.  v,  fij,'.  23. 

1837.         —     DECUSSATA,  A.  Goldfusn.     Petref.  Germ.,  vol.  ii,  p.  1(JG,  lA.  cxsviii, 

fi!,'S.  1,  2. 

—  —     coMPRESSA,  Goldfuss.     Ibid.,  p.  1(37,  pi.  cxxviii,  fig.  4. 

"r  1840.         —      PYRAMiDALis,  U.  B.  GeiiiUz.     Cbar.  d.  Scbiebt.  u.  Petref.  des  sachs. 

Kreidegeb.,  pt.  2,  p.  55,  pi.  x,  fig.  1, 

—  —     coMPEESSA,  Geinitz.     Ibid,  p.  55. 

1841.         —      FENESTRATA,  F.  A.  Buiner.  Die  Vcrsteiu.  d.  uord-deutsch.  Kreidegeb., 

p.  65,  pi.  viii,  fig.  22. 

—  —      DECUSSATA,  Bonier.     ILiiJ.,  p.  65. 

1846.         —      PYRAMIDALIS,  H.  B.  GeiuHz.     Gruudr.  d.  Versleiu.,  p.  451. 


'  I  have  not  seen  any  specimen  of  Pinna  ?  crassa,  Fittou,  *  Trans.  Geol.  Soc.,'  ser.  2,  vol.  iv  (1836). 
p.  130  ;  Morris,  '  Cat.  Brit.  Foss.,'  p.  180. 


100  CRETACEOUS   LAMELLIBRAXCHIA. 

1846.     Pinna  decussata,  A.  E.  Reuss.     Die  Versteiu.  dor  bohui.  Kreidcforuiat., 

pt.  2,  p.  14,  pi.  xxxvii,  figs.  1,  2. 
1850.         —  —  A.  (VOrhigny.     Prodr.  tie  Pal,  vol.  ii,  p.  165. 

—  —      FENESTEATA,  (V Ofbiytiij.     Ibid.,  p.  246. 

—  —      DECUSSATA,  J.  de  C.  Sowerhy,  in  F.  Diron.     Geol.  Sussex,  p.  355  (p. 

386,  ed.  2),  pi.  xxviii. 
fig.  20. 

—  —      DiLuviANA,  H.  B.  Geinitz.     Das  Quadersandst.  oder  Kreidegeb.  iu 

Deutsclilaud,  p.  166. 

—  —      FENESTKATA,  Gciiiitz.     Ibid.,  p.  166. 

1854.         —     DECUSSATA,  /.  Morfis.     Cat.  Brit.  Foss.,  ed.  2,  p.  180. 

—  —      SULCATA,  Morris.     Ibid.,  p.  180. 

1873.         —      DECUSSATA,  H.  B.  Geinitz.     Das  Elbthalgeb.  in  Sachseu  (Palipouto- 

grapliica,  vol.  xx),  pt.  i,  p.  211,  pi.  xlvii, 
figs.  4,  5  ;  pt.  ii,  p.  53,  pi.  xv,  figs.  2,  3 ; 
pi.  xvi,  fig.  1. 
1877.         —  —  A.  Fritsch.     Stud,  ini  Gebiete  der  bolim.  Kreideforiiiat., 

ii.  Weisseuburg.  u.  Maluitz.  Scliicht.,  p. 
120,  fig.  86. 
1883.         —  —  Fritsch.     Ibid.,  iii.  Iserscbicht.,  p.  104. 

1888.  —  —  G.  Mailer.  MoUusk.  d.  uutersen.  v.  Biauuscliwoig  (Jalirb. 

d.  k.  preussisch.  geol.  Landesanst.  fiir  1887), 
p.  420. 

1889.  —  —  Fritsch.     Stud,   im    Gebiete   dor  bohm.  Kreidoformat., 

iv.  Teplitz.  Scbicht.,  p.  79. 
?  1890.         —  —         M.  Blanchenhorn.     Beitr.  z.  Geol.  Syi'iens :  Kreidesjst. 

in  Mittel  u.  Nord-Svrion.  p.  80. 
1893.         —  —  Fritsch.      Stud,  ini  Gebiete  der   biihm.  Kreideforinat., 

V.  Priesen.  Scliicht.,  p.  94. 
1897.         —  -_  _  Ibid.,  vi.  Chloinok.  Sdiicht.,  p.  57. 

?  1894.         —     cf.  DECUSSATA,  A.  Henniij.     Oui  Ahussandst.  (Geol.  Foreu.  i  Stook- 

holm  Forhandl.,  vol.  xvi),  p.  522. 
1902.         —      DECUSSATA,  J.   P.  J.   Eavn.      Mollusk.  i  Danmarks  Kridtaflej.,    i. 

Lainellibr.,  p.  104. 

Non  1846.         —  —         E.  Forbes.     Trans.  Geol.  Soc,  ser.  2,  vol.  vii,  p.   1.53 

(=  P.  arata,  Forbes). 

Description. — Shell  moderately  elongate,  triangular,  laterally  compressed, 
section  rhombic,  but  becoming  lenticular  in  the  later  portion.  Dorsal  margin 
straight,  ventral  margin  slightly  curved. 

Each  valve  is  divided  into  two  nearly  equal  parts.  The  dorsal  part  is  flattened 
and  bears  from  7  to  9  strong  rounded  ribs,  separated  l)y  broad,  shallow, 
rounded  depressions.  The  distance  between  the  ribs  increases  in  passing  from  the 
apex  to  the  posterior  extremity.  In  well-preserved  specimens  linear  ridges  are 
seen  crossing  the  ril)s  and  interspiices  at  regular  intervals.     The  dorsal  portion  of 


PINNA.  101 

the  ventral  pai't  of  the  valve  bears  from  5  to  7  ribs  similar  to  those  on  tlie 
dorsal  part  and  of  nearly  uniform  size,  with  transverse  linear  i-idges.  On  the 
ventral  portion  of  the  ventral  part  of  the  valve  there  are  strong  ridges  or  folds 
which  form  an  acute  angle  with  the  last  rib,  and  curve  slightly  towards  the  umbo. 
Measurements  {approximate)  : 

(1)  (2)  (3) 

Length         .         125         .         117         .         120  mm. 
Height         .  6G         .  69         .  OG     „ 

(1)  Chalk  Marl,  Folkestone. 

(2)  Chalk,  Newtimber  (Sussex). 

(3)  Cbalk,  Trimingham. 

Bemarlis. — Most  of  the  specimens  of  Pinna  from  the  Chalk  are  very  imperfectly 
preserved,  and  it  is  not  unlikely  that  Ijctter  material  would  show  that  more  than 
one  species  could  be  distinguished. 

In  the  examples  from  Trimingham  the  ribs  are  rather  broader  and  more 
rounded  than  in  most  of  the  specimens  found  at  lower  horizons. 

Ajfinltics. — This  species  is  less  elongate  than  P.  crctacea  (Schlotlieim),'  and 
has  the  ridges  on  the  ventral  part  of  the  valves  more  distinctly  curved  than  in 
that  form.  It  has  a  larger  apical  angle  than  P.  Rohinaldina  (see  p.  0(3) ;  also  the 
shell  is  rather  more  compressed,  and  the  ribs  on  the  ventral  part  do  not  decrease 
regulai'ly  in  size  as  they  do  in  P.  Buhinaldina. 

P.  sulcata.  Woodward  (Plate  XIV,  fig.  1),  from  the  Norwich  Chalk,  as  was 
suggested  by  J.  de  C.  Sowei'by,  does  not  differ  from  P.  ilccussahi.  AVooilwnrd's 
name  is  prior  to  tliat  of  Goldfuss,  but  since  the  original  figure  was  scarcely 
sufficient  for  the  recognition  of  the  species  and  was  not  accompanied  by  any 
description,  I  do  not  think  it  is  desirable  that  the  well-knoAvn  name  P.  decussata 
should  be  displaced  by  P.  i^nlcata. 

Most  of  the  English  specimens  of  P.  dccussata  agree  better  with  the  figures 
given  by  Geinitz  (1873)  than  with  those  of  Goldfuss  and  Reuss.  I5ut  the  example 
figured  by  Dixon  seems  to  be  very  similar  to  the  types  of  Goldfuss. 

Tyi)es. — From  the  Quadersandstone  of  Haltern  (Westphalia)  and  Schandau 
(Saxony).  The  specimen  figured  by  Dixon  cannot  be  found.  The  type  of  P. 
sulcata  is  in  the  Norwich  Museum. 

Distribution. — Chalk  Marl  of  Ventnor  and  Folkestone.  TerchratuHua  zone  of 
Arn  Hill  near  Warminster.  Zone  of  Holaster  planus  of  Balsham,  Chalk  of  New- 
timber.  Zone  oi  Micro ster  cor-amjuinnm  of  Charlton  and  Graveseud.  Upper  Chalk 
(zone  of  M.  ror-tesUulinarinm  or  M.  cor-anrjuinum)  of  Swaffham,  Norfolk,  (r)  Zone 
of  Acfinocama,!'  qitadratus  of  Ea.st  Harnham  near  Salisbury.  Zone  of  Hrhmnitrlla 
mvcronata  of  Norwich.     Chalk  of  Trimingham. 

1  Gciuita,  'Das  Elbthalgeb.,'  pt.  li  (1873),  p.  54,  pi.  siv.  tii,'s.  -2,  3. 


102  CRETACEOUS   LAMELLIBRAXCHIA. 


i'V(/«i7//— ASTARTID^,  Gnnj. 
Genus — Astaete,  J.  Soicerbij,  1816. 

('  Min.  Conch.,'  vol.  ii,  p.  85.) 

Astaete  elono.vja,  iVOrhujiKj,  1844.     Plate  XIV,  figs.  2  a,  ft,  3. 

18-i2.     AsTAKTE  OBLONGATA,  Dfslwijef  ill  A.  Leijmerie.     Mem.  See.  gc'ol.  de  France, 

ser.  2,  vol.  v,  pp.  5,  24,  pi.  vi,  fig.  1 
(non  oblonga,  Sowerby,  1826). 
1844.  —         ELONGATA,  A.  i.V Orhujiiij .     Pal.  Franc.  Terr.  Cri't.,  vol.  iii,  p.  68,  pi. 

cclxiii,  figs.  8 — 11. 
1850.  —  —         iVOrhujnii.     Froclr.  de  Pal.,  vol.  ii,  p.  77. 

1855.  —  —         G.  Cotteau.     Moll.  Foss.  de  I'Yonne,  p.  69. 

1866.  —  —         F.  J.  Pidet  and  G.  Campiclu:     Foss.  Terr.  Cn't.  Ste. 

Croix  (Maler.  Pal.  Suisse,  ser. 
4),  p.  310,  pi.  cxxiv,  figs.  8,  9. 
1868.  —  —         P.  de  Loriol.     Valaugieu  d'Arzier,  p.  28,  pi.  ii,  fig.  7. 

1871.  —  —         F.  Stoliczka.     Palieout.  ludica,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  285. 
1000.  —  —         A.  WoUemanii .     Die  Biv.  u.  Gastrop.  d.  deutsch.  u.  liol- 

liind.  Neocoms  (Abhaudl.  d.  k. 
preussisch.  geol.  Land.,  N.  F.,  pt. 
31),  p.  102. 

Vcscviptluii. —  Shell  thick,  elongate,  rounded-oblong  or  oval,  convex,  compressed, 
very  inequilateral.  Postero-dorsal  margin  curving  veutrally  to  join  the  obtuse 
and  slightly  curving  posterior  margin.  Postero-ventral  extremity  rounded.  Ven- 
tral margin  nearly  straight.  Anterior  margin  rounded.  Umbones  small,  with  an 
indistinct  keel  passing  from  them  towards  the  postero-ventral  extremity.  Luiiule 
narrow. 

Ornamentation  consists  of  strong  concentric  ril)s,  somewhat  unequal  in  size,  and 
separated  by  narrow  grooves.     Margins  of  valves  creuulated. 

Length  21  mm. ;  height  22  mm. 

Affinities. — Astarte  cingvhifa,  Geinitz,'  from  the  Cenomaniau  of  Plauen,  is 
probably  identical  with  this  species. 

A.  cJoncjata  is  easily  distinguished  from  other  Cretaceous  species  by  its  elongate 
form. 

lieuiaii-.i. — The  only  specimens  seen  are  in  tlie  Museum  of  Practical  Geology. 

'  'Das  Elbthalgeb.  in  Sacliseu'  (Palasoulographica,  vol.  xx,  pt.  i,  1873),  p.  226,  pi.  1,  fig.  8.     Non 
A.  cingulata,  Coutejcau,  'Kimmerid.  de  Montbeliard '  (1859),  p.  267,  pi.  xi,  figs.  5 — 7. 


ASTARTE.  103 

One  has  the  shell  preserved,  the  others  are  internal  casts  showing  deep  muscular 
impressions. 

Tiipp.^. — Leymerie's  specimens  came  from  the  Lower  Xeocomian  of  Avalleur, 
Chenay,  and  MaroUes  (Aube).  D'Orbigny  records  specimens  from  the  Lower 
Neocomian  of  St.  Sauveur  (Yonne).  Pictet  and  Campiche  figure  specimens  from 
the  Valanginian  of  Ste.  Croix. 

Distribution. — Lower  Greensand  of  Seend. 


AsTARTE  suiiACUTA,  (VOrbigiiij,  1850.     Plate  XIV,  figs.  4 — G. 

1844.     AsTARTE  CARiNATA,  A.  (TOvhHjmj.     Pal.  Fran9.  Terr.  Crot.,  vol.  iii,  p.  fi3, 

pi.  cclxii,  figs.  1-3.  {noTiA.carwata, 
Phillips,  1829.) 
1847.  —         ACTTTA,  tVOrhigny.     Ibid.,  p.  759.     (non  A.  acuta,  Eeuss,  1846.) 

1850.  —         suBACUTA,  d'Orhiyny.     Prodr.  de  Pal.,  vol.  ii,  p.  77. 

1866.  —  —  F.  J.  Pictet  and  G.  Campiche.     Foss.  Terr.  Crct.  Sle. 

Croix  (Mater.  Pal.  Suisse,  ser.  4), 

p.  318. 
1900  —  —  A.  Wollemann.     Die  Biv.  ii.  Gastrop.   d.  deutsch.  ii. 

hoUilnd.    Neocoms     (Abhandl.    d. 

k.  preussisch.  geol.  Land.,  N.  F., 

pt.  31),  p.  99. 

Description. — Shell  triangular,  much  compressed,  length  greater  than  lieiglit, 
slightly  inequilateral.  Antero-dorsal  margin  long  and  concave.  Postero-dorsal 
margin  longer  than  the  antero-dorsal,  and  either  concave  or  nearly  straight.  Both 
of  these  margins  form  obtuse  angles  with  the  well-rounded  margin  of  tlie  ventral 
half  of  the  shell.  Umbones  vei'y  acute,  projecting,  often  nearly  median  and  not 
curved.     Lunule  narrow,  with  a  sharp  edge.     Escutcheon  ver}^  narrow. 

Ornamentation  consists  of  prominent  concentric  ribs  separated  l)y  l)road  inter- 
spaces.     The   distance  between  the   ribs   increases   in  passing  from    the    \uuho 
ventrally.     Margins  of  valves  crenulated. 
Measnreriicnts : 

(1)  (2) 

Lenerth         .         14         .         10  mm. 
Height  .         11         .  8      „ 

(1,  2)  Pt'i-Hrt-bed.  East  Sbalford. 

Affinities. — A.  snhacuta  is  distinguished  from  the  other  Cretaceous  species  by 
its  acute  umbones  and  flattened  valves. 

Ernvnis. — The  only  specimens  which  I  have  seen  are  in  the  ^Meyer  Collection, 
Sedgwick  Museum. 


104  CRETACEOUS   LAMELLIBRANCHIA. 

Tijpe. — From  the  Neocoraian  of  Brienne  (Aiilje). 

Distribution. — Perna-hed  of  East  Slialford.     Atlierfield  Beds  of  Sevenoaks. 


AsTABTE  siNUATA,  iVOrtngnij,  1844.     Plate  XIV,  figs.  7 — 9. 

1844.     AsTAETE  SINUATA,  A.  (VOrhigtiij.      Pal.  Fran9.  Terr.  Cn't.,  vol.  iii,  p.  G9,  pi. 

cclxiv,  figs.  1 — 3. 
1850.  —  —        (VOrliyny.     Proclr.  de  Pal.,  vol.  ii,  p.  118. 

1856.  —  —        F.  J.  Pktet  and  E.  Renevier.  Foss.  Terr.  Aptien  (Mater. 

Pal.  Suisse.ser.  l),p.  89, 
pi.  X,  fig.  3. 
18GG.  —  —        F.  J.  Pictet  and  G.  Campiche.     Foss.    Terr.    Crt't.    Ste. 

Croix    (Matur.     Pal. 

Suisse,  ser.  4),  p.  311. 

1871.  —  —        F.  Stoliczka.     Palocout.    ludica,   Cret.    Fauua  S.  India, 

vol.  iii,  pp.  251,  285. 
1895.  —  —        G.  Maas.     Zeitscbr.   d.    deutsch.  geol.    GeseUsch.,    vul. 

xlvii,  p.  261. 
19U0.  —  —        A.  WoUemann.      Die   Biv.    u.    Gastrop.    d.   deiitsch.  ii. 

lioUi'ind.  Neoeoms  (Abhaudl.  d.  k. 
preussisch.  geol.  Laud.,  N.F.,  pt.  31), 
p.  100. 

Deserijitiov. — Shell  siib-quadi-ate,  rounded  ventrally,  trniicated  posterioi-ly, 
longer  than  high,  slightly  or  moderately  inequilateral,  much  compressed.  A  furrow 
extends  from  just  behind  the  umbo  to  the  sinuosity  on  the  posterior  margin,  and 
cuts  off  a  triangular,  flattened,  postero-dorsal  part  of  the  valve.  Antero-dorsal 
margin  nearly  straight.  Anterior  margin  rounded,  passing  gradually  into  the 
curved  ventral  margin.  Posterior  margin  with  a  sinuosity  above  the  postero- 
ventral  ano^le.  Postero-dorsal  marg-in  straiufht  or  slisfhtlv  concave,  lonsrer  than  the 
antero-dorsal  margin,  and  forming  an  angle  with  the  posterior  margin.  Umbones 
pointed,  inconspicuous.  Limule  and  escutcheon  long,  narrow,  with  sharp  edges 
which  have  tooth-like  ^projections  where  the  ribs  end. 

Ornamentation  consists  of  rounded,  concentric  ribs  separated  by  shallow 
furrows.  The  ribs  are  rather  stronger  on  the  posterior  than  on  the  anterior  j)art 
of  the  shell,  and  are  sinuoiis  where  they  cross  the  posterior  furrow.  Smaller  i'il)s 
arc  present  on  the  main  ribs  and  furrows. 

Measurements : 


(1) 

(2) 

Length    . 

. 

K) 

15  mm 

Heiglit    . 

. 

14-5      . 

14     „ 

Tliickness 

. 

4- 

(1. 

2) 

Ci-ackeis,  Atberfield. 

ASTARTE.  105 

Affimties. — A.  miuata  is  distinguislied  from  other  Cretaceous  species  of  Astaiie 
by  tlie  furrow  passing  from  the  umbo  to  the  posterior  margin.  Conrad'  thought 
that  this  species  might  belong  to  his  genus  LirodiHciis.  I  am  unal)le  to  express  an 
opinion  on  this  matter,  since  I  have  seen  only  three  examples,  none  of  which  shows 
the  hinge,  nor  is  it  seen  in  the  figures  given  by  previous  writers. 

Type. — From  the  Aptian  of  Marolles  (Aube). 

Distribution. — Lower  Greeusand  (Crackers)  of  Atherfield.  Recorded  by  Pictet 
and  Renevier  from  the  Lower  Greensand  of  Peasmarsh. 


AsTARTE  UPWABENSis,  sp.  nov.     Plate  XIV,  figs.  lOa-r,  l\a,  b,  12. 

1883.     AsTAETE,   sp.  uov.,    W.  Keepimj.      Foss.,  etc.,  Neoc.  Upware  aud  Brickhill, 

p.  122,  pi.  vi.  fig.  9. 

Description. — Shell  ovate,  a  little  higher  than  long,  moderately  and  evenly 
inflated,  moderately  (or  sometimes  only  slightly)  inequilateral.  Dorsal  half  narrow- 
ing gradually  to  the  umbo  ;  ventral  half  larger  and  with  evenly-rounded  margin. 
Antero-dorsal  border  slightly  concave ;  postero-dorsal  border  long  and  convex. 
Umbones  curving  forward.  Luuule  large,  ovate,  depressed,  with  a  sharp  border. 
Escutcheon  lanceolate,  with  a  sharp  edge. 

Ornamentation  consists  of  many  flattened,  inconspicuous,  concentric  ribs 
separated  by  linear  grooves. 


Measurements : 

(I) 

(^)                          (3) 

(4) 

(5) 

Length 

24 

21         .         19 

14 

lo  mm. 

Height      . 

25 

21-5      .         21 
(l-.'j)  Lower  Greensand,  Upware. 

15 

14     „ 

Affinities. — This  species  presents  some  resemblance  to  -I.  nflangiensi.'i,  Pictet 
and  Campiche,'-  but  its  dorsal  half  is  not  so  luirrow  and  pointed,  and  the  antero- 
dorsal  margin  is  less  concave.  It  is  also  similar  to  A.  liliodani,  Pictet  and 
Campiche,-'  from  the  Gault  of  Gosne,  but  the  umbones  are  less  prominent. 

Astarfe  npirar''nsis  is  distinguished  from  A.  circiilaris,  Gueranger,'  by  its  ovate 
outline  and  greater  height. 

T!/2)e. — Of  the  specimens  of  this  species  which  were  figured  by  W.  Keeping  as 

'  '  Amer.  Jouru.  Couch.,'  vol.  v  (186it),  P-  46. 

-  'Terr.  Crct.  Ste.  Croix '  (Mater.  Pal.  Suisse,  ser.  4,  1866),  p.  303.  pi.  cxxiii,  figs.  3.  4. 

3  De  Loriol,  '  Gault  de  Cosne  '  (1882),  p.  94,  pi.  xii,  figs.  1-7. 

*  •  Album  Palt'ont.  de  la  Sarthe  *  (1867),  p.  12,  pi.  xv,  fig.  12,  pi.  xvi,  figs.  7.  8. 

14 


106  CRETACEOUS    lAMELLIBRANCIIIA. 

Astarte,  sp.  nov.,  one  is  in  the  Sedgwick  Museum  (fig.  9(/),  the  other  in  Mr.  J.  F. 
Walker's  collection  (fig.  \)h). 

Distrihiitioii.— Lower  Greensancl  of  Upware. 


AsTARTE  SENECTA,  sp.  uov.  [ex  Bean  MS.]     Plate  XIV,  figs.  18-20. 

1889.     AsTARTE  SENECTA  [Bean  MS.]  fi.  W.  Lnmphnjh.     Quart.  .Jouni.  Geol.  Soc, 

vol.  xlv,  p.  616. 

Descriptiun. — Shell  subtriangular,  or  approaching  subquadrangular,  .sometimes 
rounded,  rather  compressed,  usually  very  inequilateral ;  height  usually  a  little 
greater  than  length.  Anterior  margin  rounded,  ventral  margin  curving  slightly 
and  often  forming  a  rounded  angle  with  the  posterior  margin,  which  is  slightly 
curved  and  usually  makes  an  obtuse  angle  with  the  postero-dorsal  margin. 
Umbones  small,  curving  forwards.  Lnnnle  ovate,  dee]),  Avith  a  .shai'p  Ijorder. 
Escutcheon  narrow,  deep,  with  a  sharp  border. 

Ornamentation  consists  of  strong  concentric  ribs,  with  sharp  summits,  separated 
by  broad  furro\\'s,  on  both  of  which  are  numerous  small  ribs.  The  ribs  l)end 
sharply  in  passing  on  to  the  postero-dorsal  part  of  the  valve,  and  cut  the  postero- 
dorsal  margin  obliquely.      Margins  of  valves  strongly  crenulated. 

Measurements : 

(1)         (-')        (3)         W        (5)         (6) 
Lentrth        .       23       22       21       19       13       20 


(7)           (8) 

(9) 

(lU) 

(11) 

25       25 

23 

23 

-\   mm. 

22-5    22 

23 

22 

'^1 

Height        .       21-5    20       19       17       11       24 

(1-5)  Speotou  Clay,  Speeton. 
(6-11)  Claxby  Ironstone,  Benuiworth  Haven. 

Affinities. — Astarte  veneris,  Eichwald,'  is  similar  to  this  species,  but  has  a 
deeper  and  larger  lunule,  more  ]irominent  umbones,  less  compressed  valves,  and 
more  slender  ribs.  Specimens  of  A.  reiicris  from  the  '  Volgian  '  of  Moscow  are 
in  Mr.  Lamplugh's  collection. 

Bemarks. — This  species  has  been  known  to  collectors  for  a  long  time,  and  lias 
appeared  in  lists  of  fossils  under  the  name  Asturte  senecta,  Bean  MS.,  lint  has  not 
hitherto  been  described  and  figured. 

The  s})ecimens  from  the  Claxby  Ironstone  are,  as  a  rule,  more  rounded  in 
outline  than  those  from  Speeton,  and  their  ornamentation  is  not  so  well  preserved 
on  account  of  the  difficulty  of  separating  the  shells  from  the  hard  matrix  in  which 
they  are  found. 

'  D'Orbiguy,  in  Murcliisou,  de  Verueuil,  and  de  Keyserling, '  Gcol.  Euss.  d'Europe,'  vol.  ii  (1845), 
p.  456,  pi.  xxxviii,  figs.  21,  22. 


ASTARTE.  107 

Disfrihiifiou. — Zone  of  BelemniteH  latemlU :  in  tlie  Speoton  Clay  of  Speeton 
and  tlie  Claxby  Ironstone  of  Bonniworth  Haven. 


AsTARTE,  sp.     Plate  XIV,  fig-.  2 1 . 

Bescrijdion. — Shell  oval,  moderately  convex,  slightly  inequilateral,  length 
greater  than  height.  Antero-dorsal  margin  concave.  Anterior  margin  rounded, 
passing  gradually  into  the  curved  ventral  margin.  Postero-dorsal  margin  convex, 
forming  a  rounded  angle  with  the  posterior  margin.     Umbo  pointed. 

Ornamentation  consists  of  about  15  strong,  rounded,  concentric  ribs  separated 
by  rounded  furrows  of  greater  breadth.  Fine  concentric  ridges  occur  on  both  ribs 
and  furrows.  The  ribs  cut  the  postero-dorsal  margin  at  a  large  angle ;  they  are 
more  widely  separated  on  the  dorsal  than  on  the  ventral  half  of  the  valve. 

Length  12'5  mm.;  height,  112  mm. 

Bemaiis. — This  species  is  known  by  a  single  right  valve  only.  The  ornamenta- 
tion is  somewhat  .similar  to  that  of  A.  senedd,  but  the  slifll  is  more  oval  and  less 
inequilateral,  also  the  ribs  are  more  numerous  and  form  a  largei-  angle  with  the 
postero-dorsal  margin . 

Distribtttio)i. — )Speeton  Clay  of  Speeton. 


ASTARTE  C.VNTABRIGIENSIS,  Sp.  UOV.      Plate  XIV,  figS.  22(1,  h,  23  rt,  h,  24. 

1883.  AsTARTE  suBDENTATA,  W.  Keeping.  Poss.,  etc.,  Neoc.  Upware  and  Brick- 
hill,  p.  122,  pi.  vi,  6^.  11  {non 
Eonier) . 

Descnption. — Shell  subquadrate,  longer  than  high,  very  inequilateral,  moderately 
inflated,  with  the  greatest  convexity  between  the  umbo  and  the  postero-ventral 
angle.  Postero-dorsal  margin  long,  slightly  convex,  forming  an  obtuse  angle  with 
the  truncated  posterior  margin,  and  a  blunt  angle  where  it  joins  the  slightly  convex 
ventral  margin.  Anterior  margin  rounded.  Lunula  deep,  ovate,  distinctly  limited. 
Escutcheon  deep,  with  a  sharp  edge. 

Ornamentation  consists  of  strong  concentric  ribs  bearing  finer  ribs. 

Measurements  : 

(1)  (2)  (3)  (4)  (5) 

Length  .  17-5         15         15         14         14 

Height  .  K?  l:V.-.       13         12-5      12 

(1-8)  Lower  Greensand,  Upwaro. 


(15) 

(7) 

(8) 

13-5 

13 

12     mm 

12-5 

11-5 

lOo     „ 

108  CRKTACEOUS  l.AMELLIBRANCHIA. 

Abilities. — This  species  was  identified  by  W.  Keeping  with  A.  suhdentata, 
Romer,'  from  the  Neocomian  of  Brunswick.  1  have  submitted  photographs  of 
the  British  fossil  to  Dr.  A.  Wollemann  and  he  agrees  with  me  in  thinking  that  it 
is  quite  distinct  from  A.  snhdenlata.  In  the  latter  the  shell  is  smaller,  the  valves  are 
much  flatter  and  more  elongate,  and  tlic  umbones  are  more  pointed  and  less 
anterior  in  ])Osition. 

The  ornamentation,  when  avoII  preserved,  is  somewhat  similar  to  that  of  A. 
seneda  (see  above),  l)ut  the  shell  is  more  inequilateral,  more  nearly  quadrate  in 
outline,  and  the  postero-dorsal  part  is  more  compressed. 

Bemarl-s. — The  ornamentation  is  often  imperfectly  preserved,  and  in  some  cases 
it  has  almost  entirely  disappeared.     The  hinge  has  not  been  seen. 

Tijpe. — The  specimen  figured  by  Keeping  is  in  the  Sedgwick  Museum,  Cam- 
bridge. 

Distnhutiou. — Lower  Greensand  of  Upware. 


AsTAUTE  cLAXBiENsis,  sp.  nov.     Plate  XIV,  figs.  25-28. 

Description. — Shell  small,  thick,  oval,  longer  than  high,  inflated,  slightly  inequi- 
lateral. Antero-dorsal  margin  concave,  postero-dorsal  slightly  convex.  Anterior 
margin  well  rounded.  Ventral  and  posterior  margins  forming  a  regular  curve. 
Umbones  prominent,  close  together,  nearly  median,  curved  greatly  inwards  and 
slightly  forwards.  Lunule  large,  ovate,  with  sharp  edges.  Escutcheon  lanceolate, 
smooth,  distinctly  limited. 

Ornamentation  consists  of  strong,  narrow,  concentric  ribs,  separated  by  broad, 
deep  furrows.  Left  valve  with  two  stout  cardinal  teeth  and  a  tooth  at  the  niai'gin 
of  the  lunule.     Margins  of  valves  coarsely  crenulate. 

Measnremrxts  : 

(1)  (2)  (3)  (4)  (5) 

Length  .         12         .  11  .  10         .         9         .         8  mm. 

Height  .         10-5      .         10         .  9         .         8*25    .         7     „ 

(1-3,  5)  Claxby  Ironstone,  Benuiworth  Haven. 
(4)  Spilsby  Sandstone,  Spilsby. 

Affinities. — Astarte  claxbiensis  shows  considerable  resemblance  to  certain  species 
found  in  the  Jurassic  rocks ;  thus  Astarte  robusta,  Lycett,^  from  the  Cornbrash,  seems 
to  dilfer  only  in  having  the  valves  more  elongate  and  the  umbonal  parts  narrower. 

'   '  Verstein.  uorddeutscb.  Ivieidegeb.'  (1841),  p.  71,  pi.  ix,  fig.  9.     Wollemann,  '  Die  Bivalvcn  u. 
Gasterop.  d.  dcutsch.  u.  holliind.  Neocoms '  (1900),  p.  98,  pi.  v,  fig.  2. 
"  '  Suppl.  Men.  Mollusca  Great  Ool.,'  etc.  (1863),  p.  74,  pi.  xxxv,  fig.  6. 


ASTARTE.  109 

A.  cordata,  Trautscliokl/  is  another  example  of  the  same  type.  A.  Saiivagei,  de 
Loriol,'  from  the  Sequauiaii,  i.s  also  similar  to  A,  claxbienain,  but  appears  to  be  less 
elongate. 

Diiifrihutioii. — Spilsby     Sandstone    (zone    of    Beh'mnitcs  Inleraliti)    of   Spilsl:)y. 
Claxby  Ironstone  (zone  of  B.  hitcrnHx)  of  Bcnniworth  Haven. 


AsTARTE  siJBCOSTATA,  d'Ovhigny,  1850.     Plate  XIV,  figs.  29-36. 

1842.     AsTARTE  LATicosTA,  DcsJiaycs.     In  A.  Leymerie,  Mvm.  Soe.  geol.  de  France, 

ser.    2,   vol.    v,    \>.   4,  pi.    iv,  figs.  4,    5 
(uon  A.  laticosta,  Deshayes,  1839). 

1844.  —         STRiATO-cosTATA,  A.  (VOrbigny.     Pal.  Frau9.  Terr.  Crct.,  vol.  iii, 

J).  64,  1)1.  cclxii,  figs.  7-9 
(non  A.  striato-costata,  Edmer, 
1836). 

1845.  Venus  (?)  [steiato-costata],  E.  Forbes.     Quart.  Journ.  Geol.  See,  vol.  i, 

p.  241. 
1850.     AsTAETE  SUBCOSTATA,  cVOrbigmj.     Prodr.  de  Pal.,  vol.  ii,  \k  77. 

1854.  —         STEIATO-COSTATA,  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  ]>.  187. 

1855.  —         SUBCOSTATA,  G.  Cotteau.     Moll.  Foss.  de  I'Yonne,  p.  70. 

1856.  —        LATICOSTA,  F.   J.  Pidet  and  E.  Benevier.     Foss.   Terr.   Aptien 

(Mater.   Pal.    Suisse,    ser.    1),    p.    88, 
pl.  X,  fig.  2. 
1865.         —         Leymeeii,  K.  A.  Zlttd.     Die,Bivalv.  d.  Gosaugeb.  (Denkschr.  d.  k. 

Akad.  Wien,   Math.-nat.   Classe,   vol. 
xxiv),  p.  156. 

1865.  —         LATICOSTA,  H.  Coquand.     Mon.  Ajitien  de  I'Espagne,  p.  126. 

1866.  —         SUBCOSTATA,  F.  J.  Pidet  and  G.  Campiche.     Foss.  Terr.  Cret.  Ste. 

Croix  (Mater.  Pal.  Suisse,  ser.  4),  p.  307. 
?  1868.         —         STRIATO-COSTATA,  E.  Eicliwald.     Letbtea  Rossica,  vol.  li,  p.  624. 
?  1868.         —         LATICOSTA,  Ekhwald.     Ibid.,  p.  628. 

p  1900.        —        Leymeeii,    G.   Mailer.      Deutsch-Ost-Afrika,    vol.    vii,    p.   552, 

pl.  xxii,  figs.  4,  5. 
1905.         _        SUBCOSTATA,  E.  Harbort.     Die  Fauna  der  Scbauniberg-Lippe'schen 

Kreidemulde,  p.  60,  pl.  iv,  fig.  6. 

De>icription.—^\\e]\  small,  usually  rather  convex,  subquadrate  or  subtriangular, 
moderately  or  very  inequilateral.  Antero-dorsal  margin  concave.  Anterior  and 
ventral  margins  rounded.     Postero-dorsal  margin  long,  nearly  straight,  forming  an 

1  C.  Rouillier,  '  Bull.  Soc.  Nat.  Moscou,'  vol.  xix,  pt.  2  (1846),  pl.  d,  fig.  15 ;  pl.  e,  fig.  1  ;  vol.  xxi, 
pt.  1  (1848),  pp.  274,  275.     Trautschold,  Ibid.,  vol.  xxxiii  (1860),  p.  347. 

2  De  Loriol  and  Pellat,  '  Mon.  Pak'ont.  ct  Geol.  etages  sup.  Jurass.  de  Boulogne-sur-Mer'  (1874). 
p.  96,  pl.  sv,  figs.  33,  34. 


110  CRETACEOUS   LAMELLIBRANCHIA. 

angle  ■\vitli  the  posterior  margin,  which  is  more  or  less  truncated.  Umbones 
inconspicuous.  Lunule  smooth,  ovate,  rather  broad,  with  a  sharp  edge.  Escutcheon 
smooth,  deep,  long. 

Ornamentation  consists  of  7  to  9  sharp,  prominent,  concentric  ribs,  with  steep 
dorsal  and  gentle  ventral  slopes.  Interspaces  l)road.  Between  the  ribs  there  are 
three  or  four  very  small  concentric  ribs  and  numerous  fine  radial  strife. 

Measurements  .- 

Length 
Height 


(1) 

(2)                       (3) 

(4) 

7 

6         .         5-5 

5  mm. 

5 

5         .         4-5 

4-5  „ 

(1) 

Atberfield  Beds,  Sevenoaks. 

(2) 

Atherfield  Beds,  Peasinarsh. 

(3,4) 

Per7ia-hed,  East  Shalford. 

Affinities. — This  species  resembles  Astarfe  frnnosa  (see  p.  112)  Ijut  is  larger, 
less  triangular  in  outline,  with  a  larger  apical  angle  and  fewer  ribs.  yl.  si)nilis, 
Goldfuss,'  belongs  to  the  same  group,  l)ut  is  more  rounded  in  outline,  and  has  more 
numerous  ribs  than  A.  siiljcostata. 

Forbes  states  that  English  examples  of  this  species  were  identified  by  d'Orbigny 
as  /].  nnmisvialix,  d'Orbigny,-  but  adds  that  they  resemble  much  more  nearly 
d'Orbigny's  A.  striato-costata.  They  differ  from  the  figures  oi  A.  numismalis  given 
by  d'Orbigny  in  being  less  triangular,  and  in  having  the  posterior  end  more 
truncated ;  also  the  ribs  are  less  numerous  but  more  prominent,  and  form  a  larger 
angle  with  the  postero-dorsal  margin.  English  examples  were  also  seen  by  Pictet  and 
Renevier,  and  were  identified  by  them  with  Astarte  laticosta,  Deshaycs  (=  striato- 
costata  and  suhcnntata,  d'Orbigny).  The  specimen  figured  by  d'Orbigny  is  more 
elongate  than  most  of  the  English  examples,  but  agrees  in  this  respect  with  some 
found  in  the  Atherfield  Clay  of  Sevenoaks.  The  specimens  figured  by  Leymerie 
are  much  larger  than  the  English  examples,  and  the  ribs  are  more  numerous  and 
less  prominent.  Some  of  the  differences  seen  in  the  figures  of  the  authors  quoted  in 
the  synonymy  are  probably  due  to  the  differences  in  the  age  of  the  specimens.  In 
the  young  specimens  the  posterior  end  is  more  rounded,  in  old  specimens  it  is 
more  truncated. 

Bemarl-s. — Specimens  which  occur  in  the  Crackers  of  Atherfield  (Plate  XV,  figs. 
1 ,  2)  differ  slightly  from  those  described  above,  but  probably  constitute  only  a  local 
variety ;  the  valves  are  not  quite  so  convex,  the  ribs  are  rather  more  numerous  and 

'  Tor  figures  and  references  see  Holzapfel,  '  Die  Mollusk.  Aachen.  Kreide '  (Palaeontographica,  vol. 
XXXV,  1889),  p.  194,  pi.  xix,  figs.  11—15.  A.  similis  was  referred  to  the  genus  Gouldiahy  Stoliczka : 
Holzapfel  discusses  this  subject,  and  I  am  in  agreement  with  his  conclusions. 

-  '  Pal.  Pran9.  Terr.  Crut,,'  vol.  iii  (1844),  p.  03,  pi.  cclxii,  figs.  4—0;  Pictet  and  Campichc,  'Terr. 
Crct.  Ste.  Croix'  (1800),  p.  309. 


ASTARTE.  ]  ]  1 

less  prominent,  and  the  posterior  end   of  tlie  shell   is  rather  moiv  pointed.     This 
form  resembles  A.  (nu/iihtln,  (Jueranger.' 

Ti/pes.— The  types  of  .1.  laticosi,,  came  from  the  Neocomian  of  Ohaoui-ce  and 
Jully  (Aube).  D'Orbigny's  specimens  of  A.  striato-costata  were  obtained  from  the 
Neocomian  of  Marolles  (Aube),  Attanconrt  (Hante-Marne),  and  Saint-Sanvenr 
(Yonne).  The  specimens  described  by  Forbes  are  in  the  Mnsenm  of  the  Geological 
Society  (No.  2181). 

DUnbution.—AthevRcld  Beds  of  Peasmarsh  and  Sevenoaks.  J'eniM-hcd  of  East 
Shalford,  and  probably  Atherfield.  Recorded  by  Topley  from  the  Atherfield  Beds 
of  Haslemere,  and  the  Hythe  Beds  of  Lympue. 


AsTARTE,  sp.     Plate  XV,  figs.  3,  4. 

Some  specimens  from  the  Folkestone  Beds  of  Folkestone  are  very  similar 
to  J.  suhcostata,  d'Orbigny,  but  are  lai'ger,  less  elongate,  and  have  a  smaller 
apical  angle. 


AsTAUTK  Omaijoidks,  sp.  nov.  [ex  flunh/cr  MS.].     Plate  XV,  figs.  5-7. 

DpscripHon. — Shell  small,  triangular  or  sul>quadrate,  compressed,  slightly 
inequilateral,  height  and  length  nearly  equal.  Dorsal  half  of  valves  pointed. 
Antero-dorsal  margin  slightly  concave;  postero-dorsal  margin  rather  longer  and 
nearly  straight,  the  remaining  margin  forming  a  regular  curve.  Umbones  pointed. 
Margins  of  valves  finely  crenulate. 

Ornamentation  consists  of  a  few  (usually  6  or  7)  prominent,  sharp,  concentric 
ribs,  with  steep  dorsal  slopes  and  more  gentle  ventral  slopes.  Interspaces  vci'v 
broad.  The  ribs  become  more  distant  from  one  another  in  passing  from  the  uniljo 
to  the  ventral  margin.    A  few  very  faint  concentric  ribs  are  sometimes  present  also. 

Measurements  ; 

(1)  (2)  (3) 

Length  .         5-0         .         4-25         .         4-0  mm. 

Height  .         4-75       .         4-25         .         4-0    „ 

(1—3)  Gault,  Folkestone. 

AlJhiities. — This  species  is  closely  allied  to  A.  sithcoatiitii.  (see  j).  lO'.t),  but  is 
relatively  shorter  and  less  convex,  and  has  a  smaller  ai)ical  angle  and  rather  fewer 
ribs. 

1  'Album  I'ali'out.  Jo  la  Sarthc  '  (.1«(37),  p.  13,  pi.  xvi,  ii^f.  5. 


112  CRETACEOUS    LAMELLIBRANCHIA. 

Remarls. — Hince  the  name  Omalioides  has  been  used  in  stratigraphical  lists, ^  it 
seems  desirable  to  retain  it,  although  its  construction  is  not  in  accordance  with  the 
recommendations  of  the  International  Congress  of  Zoology. 

Distribution. — Gault  (zones  vii,  x,  and  xi)  of  Folkestone. 


AsTABTE  FOKMOSA,  Soivevhi/,  183G.     Plate  XV,  figs.  8-13. 

18-36.     AsTARTE  FORMOSA,  /.  de  C.  Sowerhy.     Traus.  Geol.  Soc,  ser.  2,  vol.  iv.,  pp. 

2.39,  341,  pi.  xvi,  fig.  16. 
1842.  —  —        F.  Bomer.     De  Astartarum  Genere,  p.  21. 

1850.  —  —A.  d'OrhHjny.     Prodr.  de  Pal.,  vol.  ii,  p.  160. 

1854.  —  —J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  186. 

1871.  —  —       F.  Sfoliczka.  Palaeont.  Indica,  Cret.  Fauna  S.  India,  vol. 

iii,  p.  285  (:''  Gouldia). 

Nou  1842.  —  —       H.  B.  Geiiiitz.     Char.  d.  Scbicht.  u.  Petref.  des  sachs.- 

bohm.  Kreidegeb.,  pt.  3,  p.  7G,  pi.  x.\i, 
fig.  19  (see  Geinitz,  Elbthalgeb.  i,  i>. 
227). 
—    1844.  —  —A.  d'Orhi(jnij.     Pal.  Franf.  Terr.  Cre't.,  vol.  iii,  p.  65,  j.l. 

cclxii,    figs.    10 — 12    {A.    siihformusa, 
d'Orb.,  1850). 

Description . — Shell  small,  rather  convex,  sub-triangular,  moderately  inequilateral. 
Antero-dorsal  margin  slightly  concave.  Anterior  and  ventral  margins  forming  a 
regular  curve.  Posterior  margin  less  curved,  often  truncated,  and  forming  an 
obtuse  angle  with  the  long  and  slightly  convex  postero-dorsal  margin.  Uml^ones 
pointed.  Lunule  large,  ovate,  depressed,  smooth,  with  a  sharp  border.  Escutcheon 
long,  lanceolate,  depressed,  smooth,  with  a  sharp  border.    Margins  of  valves  smooth. 

Ornamentation  consists  of  strong  concentric  ribs  with  sharp  summits,  separated 
l)y  broad  concave  interspaces.  The  rilxs  end  abi'uptly  at  the  margins  of  the  linuilf 
and  escutcheon.     On  the  riljs  and  interspaces  fine  concentric  ridges  may  be  seen. 

Measurements  : 

(1)  (2)  (3)  (4) 

Length        .     5-0     .     475     .     4-5     .     4-0 
Height         .     4-5     .     4-5       .     4-0     .     3-75 

(1 — 6)  Blackdown. 

Affinities. — A.furniosu  is  smaller  and  has  more  numerous  ribs  than  A.  suhfurnwsa, 
1  Price,  '  The  Gault '  (1879),  p.  58  ;  Jukes-Browne,  '  Cret.  Eocks  of  Britain,'  vol.  i  (1900),  p.  465. 


(5) 

3-2.5 

(0) 

.     3-0  mm 

3-0 

,     2-5     „ 

ASTARTE.  113 

d'Orbigny.^  J.  acuta,  Reuss,-  is  another  allied  form,  Ijut  possesses  fewer  ribs  than 
A.  formosa.     See  also  A.  suhcostata  (p.  109). 

Ti/pe. — From  Blackdown,  in  the  Bristol  Museum. 

Disfribatio)i. — Upper  Greensand  (zone  of  Schlocnhaclila  rodraia)  of  Blackdown 
and  Haldon. 


AsTAETE  IMPOLITA,  Soiccvhij,  I80G.     Plate  XV,  fig.  1-1. 

1836.     AsTARTE  IMPOLITA,  /.  cle  C.  Sowerhij.     Trans.  Gool.  Soc,  ser.  2,  vol.  iv, 

pp.  239,  341,  pi.  xvi,  fig.  18. 
1854.  —  —         /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  187. 

The  only  example  of  this  which  I  have  seen  is  the  type  specimen  from  the 
Greensand  of  Blackdown.^  Both  valves  are  present,  but  the  parts  near  the  umbo 
and  lunula  are  missing.     The  specimen  is  in  the  Bristol  Museum. 


Sub-genus — Eriphyla,  W.  M.  Gabh,  1864. 

(' Geol.  Surv.  California,  Palscout.,'  vol.  i,  p.  18U.     Stoliczka,  '  Palajout.  ludica,  Cret.  Fauua,  S.  India,' 

vol.  iii,  1870,  p.  156.) 

AsTARTE  (Eriphyla)  obovata,  Sunrrbi/,  1822.     Plate  XV,  figs.  15-18.     I'late  XVI, 

figs.  1-3. 

1822.     AsTARTE  OBOVATA,  /.  (le  C.  Soiverby.     Min.  Couch.,  vol.  iv,  p.  73,  pi.  cccliii. 

1842.  —  —         F.  Rimer.     De  Astartaruin  Genere,  p.  22. 

184.0.  —  —         E.  Forbes.     Quart.  Journ.  Gool.  Soc,  vol.  i,  p.  241. 

1850.     CoKBis  OBOVATA,  ^1.  (VOrhignij.     Prodr.  de  Pal.,  vol.  ii,  p.  78. 

1852.     AsTARTE  Bkunneei,  F.  J.  Piciet  and  W.  Rotu.     Moll.  Foss.  Grts  verts  de 

Geneve,  p.  435,  pi.  xxxii,  fig.  3. 
—  —        GURGiTis,  Piciet  and  Roux.     lljid.,  p.  436,  pi.  xxxiii,  fig.  1. 

1854.  —         OBOVATA,  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  187. 

1857.  —  —         F.J.PictetamlE.Eeiievier.     Foss.  Terr.  Aptieu  (Miitt'r. 

Pal.  Suisse,  ser.  1),  p.  86,  pi.  xi,  fig.  1. 


>  '  Prodr.  de  Pal.,'  vol.  ii  (1850),  p.  77. 

=  '  Die  Versteiu.  der  bolini.  Kreideionnat.,'  pt.  2  (1846).  [>.  3,  pi.  xxxiii.  fig.  17;  ]<].  xxxvii,  fig.  14; 
NGtling,  'Die  Fauna  d.  baltisch.  Cenomau.'  (Paloeont.  Abhandl.,  vol.  ii,  1885),  p.  28.  \<\.  v,  fig.  1. 
According  to  Niitliiig,  A.  jilauoisis,  Geiuitz,  is  a  svnouyni  of  A.  acuta. 

'  Astarle  miiltistriata  was  also  described  bv  J.  de  C.  Sowerbv  from  Blackdowu,  but  I  liave  not 
seen  any  example  of  it.  See  'Trans.  Geol.  Soc.,'  ser.  2,  vol.  iv.  ]ip.  '240,  341,  I'l.  xvi,  fig.  17  ;  Morns, 
'Cat.  Brit.  Foss.,'  ed.  2  (1854),  p.  187. 

1.') 


114  CRETACEOUS    LAMELLIBRANCHIA. 

?  I860.     AsTiRTE  OBOVATA,  H.    Coqiiand.      Mou.    Aptieu    de    rEspague,    p.    I'l'l. 

pi.  xiii,  figs.  3,  4. 
1866.  —  —        F.  J.  Pidct  and  G.  Campiclie.     Foss.  Terr.  Crct.  Ste. 

Croix  (Mater.  Pal.  Suisse,  sur.  4),  p.  312. 
1871.  —  —         (Ebyphyla),  2*'. /S<oZic«A;a.  PaliBont.Indica.Cret.Fauua. 

S.  ludia,  vol.  iii,  p.  *285. 
1892.  —  —         0.  Buhrciidscn.     Zeitscbr.  d.  deutsch.  geol.  Gesellsch., 

vol.  xliv,  p.  22. 

Description. — Shell  large,  oval,  transverse,  moderately  inflated,  very  ineciui- 
latcral.  Anterior  margin  rounded,  concave  in  front  of  the  nmbo.  Behind  the 
umbo  the  dor.sal  margin  has  a  gentle  and  regular  curve.  Posterior  margin  roumled 
or  sub -truncate.  ITmbones  prominent,  curving  forward.  Lunule  deep.  Escutcheon 
narrow,  deep. 

Ornamentation  consists  of  numerous,  strong,  close,  somewhat  irregular  concent  i-ic 
ribs,  on  which  fine,  concentric,  linear  ribs  occur. 

Measurements : 

(1)  (2)  (3)  (1)  (0)  (6) 

Length  .    .  75  .  74  .  73  .  70  .  72  .  71  mm. 
Height  .    .  62  .  58  .  CO  .  59  .  63  .  59  „ 

(1-4)  Per«n-bed,  Atlierfield. 
(5,  6)  Per»a-bed,  Sandown. 

Affinities. — Astarte  Beaumonti,  Leymerie,'  and  A.  transversa,  Leymerie,-  are 
closely  allied  to  A.  ohovata,  and  were  regarded  by  Forbes  as  merely  varieties  of  the 
latter.  Pictet  and  Renevier  (1857)  were  inclined  to  regard  the  differences  as  not 
of  specific  importance.  Pictet  and  Campiche  (1866),  however,  kept  the  three  forms 
distinct,  but  wei^e  uncertain  whether  they  should  be  regarded  as  species  or  varieties. 
They  state  that  in  A.  Beaumontl  the  margin  is  smooth,  Avhilst  in  A.  obooata  and 
A.  transversa  it  is  crenulated.  In  the  first  two  forms  the  posterior  margin  i.s  nioi-e 
rounded,  Ijut  in  the  last  it  is  more  truncate.  It  is  very  doubtful  whether  the 
crenulation  of  the  margin  is  a  feature  of  specific  importance  in  Astarte;  indeed, 
one  writer^  thinks  that  it  is  a  characteristic  of  sex.  Whether  the  other  differences 
are  of  specific  value  can  be  determined  only  by  the  comparison  of  a  number  of 
examples  of  A.  Beaumunti  and  A.  transversa  with  specimens  of  A.  ohovata. 

1  '  Mem.  Soc.  geol.  de  France,'  vol.  v  (1842),  pp.  4,  24,  pi.  iv.  fig.  1.  D'Orbigny,  'Terr.  Cret.,' 
vol.  iii  (1844),  p.  60,  pi.  eclx.  Pictet  and  Campiche,  'Terr.  Cre't.  Ste.  Croix'  (1866),  p.  300,  pi.  cxxiv, 
fig.  1.     WoUemaun,  '  Biv.  u.  Gastrop.  d.  deutsch   «.  hoUiiud.  Neocoms '  (1900),  p.  95. 

'■^  Op.  cit.  (1842),  pp.  4,  24,  pi.  v,  fig.  5  D'Orbigny,  "p.  cit.,  p.  61,  pi.  cclxi.  Pictet  and  C.impiche, 
op.  cit.,  p.  301,  pi.  exxiv,  fig.  2.  De  Loriol,  '  Auim.  Invert.  Foss.  Mt.  Salcve '  (1861),  p.  68, 
pi.  viii,  fig.  9. 

■'  A.  Ostrooumoff,  'Zool.  Anzeiger,'  vol.  xxiii  (1900),  p.  499. 


ASTARTE.  115 

The  shallow  pallial  sinus  shown  in  internal  casts,  and  the  characters  of  the  hinge 
seem  to  warrant  the  reference  of  this  species  to  the  sub-genus  Eriphyla. 

Remarl-fi. — Some  of  the  specimens  found  in  the  Isle  of  Wight  have  the  posterior 
end  rounded,  but  in  the  larger  number  it  is  more  or  less  distinctly  truncated.  The 
former  approach  A.  Bcaumovii ;  the  latter  resemble  A.  transversa.  1  liave  not  seen 
any  examples  from  the  Isle  of  Wight  which  show  the  internal  margin  of  the  valve 
sufficiently  clearly  to  determine  whether  it  is  crenulate  or  not,  but  in  an  internal 
cast  from  the  Hythe  Beds  of  Hythe  (Museum  of  the  Geological  Society,  No.  2187) 
tlie  crenulation  is  distinct. 

The  specimens  of  A.  ohucata  show  a  fairly  large  amount  of  variation.  In  some 
the  anterior  part  of  the  valve  is  quite  short,  as  in  Leymerie's  figure  of  .1.  irniis- 
versa;  in  others  it  is  much  longer.  The  relative  height  and  length,  the  amount 
of  rounding  or  truncation  of  the  posterior  margin,  and  the  coarseness  of  the 
ornamentation  also  vary. 

The  specimens  from  the  Hythe  Beds  of  Hythe  are  very  poorly  preserved. 
Those  from  the  Greensand  of  Blackdown  and  Haldon  appear,  so  far  as  one  can  tell 
from  the  few  perfect  specimens  available,  to  be  rather  shorter  than  most  of  the 
Lower  Greensand  examples. 

Types. — The  type  cannot  be  found ;  it  came  from  the  Peyna-bed  of  Sandown. 

Distnhution. — Lower  Greensand  {Perna-hed)  of  Atherfield  and  Sandown. 
Recorded  by  Topley  from  the  Atherfield  Beds  of  Peasemarsh  and  Shalford,  and 
from  the  Hythe  Beds  of  Hythe  and  Lympne. 

Upper  Greensand  (zone  of  Schkv.nhacJda  rust  rata)  of  Blackdown  and  llaldon. 


AsTAR'i'E   (Eripiiyla)  l^vis  {Phillips),  1829.     Plate  XVI,  figs.  6-7.     Plate  XVII, 

fig.  1. 

1829.     Crassina  l«vis,  J.  Phillips.     Gcol.  Yorks.,  p.  122,  pi.  ii,  fig.  19  {V  fig.  18). 
1835.     AsTARTE  LiEvis,  Phillips.     Il.i.l.,  c.l.  2,  pt.  1,  p.  158  (ed.  3,  1879,  p.  252). 
1854.  —  —      /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  187. 

Description.— fiheW  large,  thick,  convex,  ovate,  usually  considerably  inequilateral; 
height  and  length  nearly  equal,  or  the  height  may  be  rather  greater  than  the  length 
or  vice  veisd.  Antero-dorsal  margin  rather  long  and  slightly  concave;  postero- 
dorsal  margin  very  long  and  moderately  convex.  Anterior  and  ventral  margins 
well  rounded.  Posterior  extremity  rounded  or  sometimes  subangular.  Urabones 
large.  Lunule  large,  ovate,  deep,  nearly  smooth,  with  a  sharp  border.  Escutcheon 
narrow,  deep. 


lie.  CRETACEOUS   LAMELLIBRANCHIA. 

Ornamentation  consists  of  numerous,  rather  strong,  narrow,  concentric  ribs 
■which  are  somewhat  irregular. 

Hinge-plate  broad,  triangular.  In  the  left  valve  two  strong  cardinal  teeth  and 
one  lateral  at  the  margin  of  the  lunule.  Teeth  of  right  valve  not  seen.  Margins 
of  valves  strongly  crenulate. 

MeasuremcnU : 

(1)  (2)  (3)  (4) 

Length         .         57         .         51         .         51         .         44  mm. 
Height         .         59         .         56         .         47         .         39    „ 

(1-4)  Claxhv  Ironstone,  Benniworth  Haven. 

Affinities. — This  species  is  allied  to  Jsfurte  Salvia inii,  de  Loriol,'  of  which  good 
specimens  are  found  in  the  Portland  Sands  of  Swindon.  In  some  cases  the  resem- 
blance is  very  close,  but  generally  the  umbones  are  more  prominent,  the  antero- 
dorsal  margin  relatively  longer,  and  the  valves  more  convex  in  A.  la^ris  than  in 
A.  Ssemaitni. 

A.  Buchi,  Romer,^  is  apparently  allied  to  A.  IkvIk,  liut  is  distinguished  by  the 
greater  anterior  curvature  of  its  umbones.  A.  ijvjantea,  Leymerie,^  is  less  inequi- 
lateral and  more  elongate  than  A.  Iseds. 

Remarks. — Most  of  the  examples  of  this  species  have  been  obtained  from  the 
Claxby  Ironstone.  Oidy  two  have  been  seen  from  the  Speeton  Clay,  one  being  in 
the  Leckenby  Collection  (Sedgwick  Museum),  the  other  in  Mr.  Lamplugh's  Col- 
lection ;  these  appear  to  agree  with  the  larger  example  of  Asturfe  la^vis  figured  by 
Phillips  (fig.  19). 

Types. — The  type,  from  the  Speeton  Clay,  appears  to  be  missing. 

Distribiition. — Claxby  Ironstone  (zone  of  Belemnites  laternHs)  of  Benniworth 
Haven.     Speeton  Clay  of  Speeton. 


AsTARTE  (Ekipiiyla)  STRIATA,  Sowcrby,  1826.     Plate  XVII,  figs.  2-7. 

182G.     AsTARTE  STRIATA,  /.  lie  C.  Sowerby.     Min.  Conch.,  vol.  vi.,  p.  36,  \>\.  dxx, 

fig.  1. 
1836.  —         CONCINNA,  /.  dt;  C.  Sowerhy.     Trans.  Geol.  See,  ser.   2,  vol.  iv, 

pp.  239,  341,  pi.  xvi,  fig.  15. 
1842.  —  —         F.  Edmer.     De  Astartariun  Generc,  p.  21. 

1  De  Loriol  and  Pellat,  '  Portlandien  de  Boulogne- su r-mer '  (1866),  p.  68,  pi.  vi,  fig.  9.  E.  G. 
Skeat  and  V.  Madsen,  '  Jur.  Neoe.  and  Gault  Boulders  in  Denmark'  (1898),  p.  123,  pi.  iii,  fig.  2. 

-  '  De  Astartarum  Gonere  '  (184-2).  p.  20,  fig.  4.  Pictet  and  Rcnevier,  '  Poss.  Terr.  Aplien'  (1856), 
p.  85,  pi.  X,  fig.  1. 

'  For  references  see  Pictet  and  Campiclie,  '  Terr.  Cret.  Ste.  Croix'  (1866),  p.  298. 


ASTARTE.  1  ]  7 

1850.     AsTARTE  STRIATA,  A.  d'Orhifjiuj.     Prodr.  de  Pal.,  vol.  ii,  p.  160  (partim). 

—  —         CONCINNA,    (VOrhigmj.     Ibid.,  p.  160. 

1854.  —         STRIATA,  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  187. 

—  —         CONCINNA,  Morris.     Ibid.,  p.  186. 

1866.  —         STRIATA,  F.   J.   Pictel  and  G.  Campiche.     Foss.  TeiT.  CrOt.  Ste. 

Croix  (Mater.  Pal.  Suisse,  ser.  4),  p.  230. 
1871.  —  —      (Eryphila),  i^.  iS'foHczi-a.     Palseont.  ludica,  Cret.  Fauna 

S.  India,  vol.  iii,  p.  285. 

—  —         CONCINNA  (Eriphyla),  Stoliczku.     Ibid.,  p.  285. 

?  1873.     Eriphyla  striata,  H.  B.  Oeinitz.     Das  Elbthalgeb.  in  Sachsen  (Palseon- 

tographica,  vol.  xx,  pt.  1),  p.  228, 
pi.  li,  figs.  1-3. 

Description. — Shell  with  rounded  outline,  sometimes  nearly  orliicular,  usually 
only  moderately  inequilateral,  moderately  convex.  Length  usuallj^  a  little  greater 
than  height,  but  occasionally  less.  The  margin  in  front  of  the  umbo  is  concave 
for  a  short  distance ;  behind  the  umbo  it  is  convex ;  the  anterior,  the  ventral,  and 
posterior  margins  form  a  more  or  less  regular  curve.  Umbones  rather  small, 
placed  a  little  in  front  of  the  median  line.  Lunulc  small,  deep,  with  a  sharp  edge. 
Escutcheon  narrow. 

Ornamentation  consists  of  numerous  small  concentric  ribs,  wliicli  are  slightly 
irregular  and  are  separated  l^y  linear  grooves;  at  intervals  somewhat  deeper 
grooves  may  occur. 

Hinge-plate  wide.  Two  cardinal  teeth  in  each  valve,  and  one  lateral  tooth 
next  the  lunule  in  the  left  valve.  Adductor  impressions  deep,  the  anterior  some- 
what elongated.     Pallial  sinus  shallow,  rounded.     Margins  of  valves  smooth. 

Measurements  : 

(3)  (4)  (5) 

44     .     42     .     39 

41     .     43     .     37 

(1-8)  Blackdown. 

Affiiiifies.~Th\s  species  is  closely  allied  to  A.  (Eriphi/h)  lenticularis  (Goldfuss),' 
but  the  outline  of  the  valve  is  less  regularly  orl)icular. 

Asfdiie  Koniad-i,  d'Archiac,-  from  the  Tourtia  of  Touruay,  was  regarded  by 
d'Orbigny,  Pictet  and  Campiche,  Stoliczka,  and  Geinitz  as  a  synonym  of  A.  striata. 
I  have  not  seen  any  exam|)le  of  the  former,  but  it  appears  to  differ  from  .1.  .•<triata 
in  having  less  prominent  umbones,  more  inflated  valves,  a  more  regularly  orbicular 

1  'Petref.  Germ.,'  vol.  ii  (1840),  p.  228,  pi.  cxlvi,  fig.  16.  Holzapfel,  'Zeitschr.  d.  doutsch.  geol. 
Gesellscb.,'  vol.  xxxvi  (1884),  p.  458,  pi.  vi,  figs.  1,  2,  and  '  Palseontographica,'  vol.  x.xxv  (1889), 
p.  195,  pi.  xiv,  figs.  5-7. 

«  'Mi'm.  Soc.  geol.  de  France,'  ser  2,  vol.  ii  (1847),  p.  302,  pi.  xiv,  fig.  4. 


(1) 

(2) 

Length     . 

46 

.     45 

Height     . 

45     , 

.     42 

(G) 

(7) 

(8) 

37     , 

.     35     . 

28     mm 

34     , 

.     34-5 . 

27-5    „ 

118  CRETACEOUS   LAMELLIBRANCHIA. 

outline,  and  apparently  also  fewer  ril)s.  Two  imperfect  specimens  from  the 
Cenomanian  (Bed  11)  of  Dunscombe  were  referred  to  A.  Komnchi  hy  tlie  late 
C.  J.  A.  Meyer,  but  tliey  are  less  convex  than  that  species  aiid  seem  to  agree 
more  nearly  with  A.  xtriafa. 

Astarte  concinna,  Sowerby,  was  regarded  by  Stoliczka  as  probal)ly  identical  with 
A.  striata.  It  is  known  by  the  type  specimen  only,  and  agrees  with  A.  striata, 
except  that  it  is  rather  higher  and  more  inequilateral.  I  believe  that  it  is  merely 
an  individual  variation  of  A.  striata. 

Types. — From  Blackdown,  in  the  British  Museum.  The  type  of  A.  concivna  is 
from  Blackdown  and  is  now  in  the  Bristol  Museum. 

Distrihutioii. — Upper  Greensand  (zone  of  Sclihrnliacliin  msfrata)  of  Blackdown. 


Genus— Oris,  M.  J.  L.  Defrance,  182-5. 
('  Diet.  Sci.  nat.'  vol.  xxxvi,  p.  219.) 

Oi'is  NEOCOMiENSis,  d'Orhigny,  1844.     Plate  XVII,  figs.  8-12. 

1842.     Opis  a.  Leymerie.     Mem.  Soc.  geol.  dp  France,  ser.  2,  vol.  v, 

p.  25,  pi.  vii,  fig.  4. 
1844.       —     NEOCOMIENSIS,  A.  cVOrlngny.     Pal.  Fran9.  Terr.  Crct.,  vol.  iii,  p.  51, 

pi.  ccliii,  figs.  1 — 5. 
1850.       —  —  d'Orbigny.     Prodr.  de  Pal.,  vol.  ii,  p.  76. 

1855.       —  —  G.  Coitcau.     Moll.  Foss.  de  IToune,  p.  67. 

1857.       —  —  F.J.  Pictet  and  E.  Renevicr.  Foss.  Terr.  Aiptien{Mat6r. 

Pal.  Suisse,  ser.  1),  p. 
83,  pi.  ix,  fig.  7. 
1861.       —    Desoei,  p.  (le  Lorinl.     Anim.  Invert.  Foss.  Mt.  Saltve,  p.  66,  pi.  viii, 

figs.  4—7. 
1866.       —    NEOCOMIENSIS,  F.  J.  Pictet  and  G.  Campiche.     Foss.  Terr.  Crt't.  Ste. 

Croix  (Mator.  Pal.  Suisse,  ser.  4), 
p.  324,  pi.  cxxv,  figs  3,  4. 
1868.       —  —  P.  de  Lorinl.     Valangien  d'Arzier,  p.  31. 

9  1871.       —  —  W.  A.  Ooster.     Protozoa  Helvet.,  vol.  ii,  p.  101,  pi.  xv, 

fig.  17. 
1883.       —  —  W.  Keeping.     Foss.  etc.,  Neoc.  Upware  and  Brickhill, 

p.  121,  pi.  vi,  fig.  8. 
1900.       —  —  A.  Wollemann.     Die  Eiv.  u.  Gastrop.   d.    clcutscli.   u. 

liolliind.  Neocoms  (Ablumdl.  d.  k. 
preussisch.  geol.  Land.,  N.  F.,  pt. 
31),  p.  102. 

Description. — Shell    trigonal    or    sub-quadrilateral,    much    higher    than    long, 
inequilateral,  greatly  inflated,  but  with  flattened  sides.     Anterior  margin  rounded. 


OPIS.  119 

Posterior  margin  truncated,  slightly  concave,  forming  an  angle  with  the  gently 
curved  ventral  margin  and  also  with  the  postero-dorsal  margin.  Umbones 
prominent,  slender,  greatly  incurved,  almost  touching  in  the  young,  Ijut  separated 
in  older  specimens.  A  prominent  carina  extends  from  the  umbo  to  the  postero- 
ventral  angle,  cutting  off  an  area  which  is  divided  into  two  parts  by  a  prominent 
but  rounded  carina  which  ends  at  the  postero-dorsal  angle ;  the  outer  part  only  of 
the  area  is  seen  in  a  side  view,  and  is  concave  ;  the  inner  part  is  depressed,  and  its 
dorsal  portion  is  flattened  and  resembles  a  lunule.  Lunide  very  large,  cordate, 
flattened. 

Ornamentation  consists  of  many  small  concentric  ril)s  se])arated  by  narrow 
grooves.  Behind  and  in  fi'oiit  of  the  flattened  jiart  of  tlie  valve  this  (irnaineiitatidii 
becomes  less  distinct  or  may  disappear  altogether.     Margin  of  valve  entire. 

Measurements  : 

(1)  (2)  (3)  (4)  (5) 

Length         .       23       .       22       .       20       .       14  .  14  mm. 

Height'        .       35       .       33       .       29       .       20-5  .  l'.»     „ 

Thickness     .       26       .       26       .       24       .       16  .  15     „ 
(1 — 5)  Lower  Greeusaucl,  Upware. 

Affinities. — This  species  shows  some  resemblance  to  0.  Hnganliana,  d'Orbigny,- 
from  the  Gault. 

Eemarlis. — The  shell  is  relatively  higher  in  large  than  in  small  specimens.  In 
all  the  examples  obtained  from  Upware  the  shell  is  preserved.  Specimens  irom 
Seeud  are  in  the  Museum  of  Practical  Geology. 

Ti/jyes. — Leymerie's  specimen  came  from  the  Lower  Neocomian  of  Bernon 
(Aube).  D'Orbigny's  specimens  were  obtained  fi'om  Saint  Sauveur  (Yonue), 
Bernon,  and  Marolles.  The  specimen  figured  by  Keeping  is  in  the  Sedgwick 
Museum. 

Dii^friliiition. — Lower  Greensand  of  Upware  and  Seend.  Internal  casts, 
prolnil)ly  belonging  to  this  species,  are  found  in  the  Lower  Greensand  of  Colesliill 
near  Faringdon. 


OpIS  IIALDONEXSIS,  sp.  uov.      Plate  XVIII,  fig.  1  ii-(J. 

DesrHjifion. — Shell  trigonal,  liigher  tlian  long,  moilerately  inenuilateral,  convex, 
wilh  flattened  sides.     Anterior  margin  slightly  convex,  passing  gradually  into  the 

'  Measured  from  tlie  umbo  to  the  postero-veutral  angle. 

i  Syn.  0.  SahandUina,  cVOrbiguy,  'Pal.  Frau^.  Terr.  CrOt.,'  vol.  iii  (1844).  p.  53,  pi.  cclvii.  figs. 
4-6  ;  Pict«t  auJ  Roux,  '  Moll.  Foss.  Grcs  verts  de  Geneve'  (1852),  pp.  432— 434.  pi.  xxxii.  tig.  1. 


120  CRETACEOUS    LA.MEJ.LIBRAX('HIA. 

sliglitly  curved  ventral  margin.  Posterior  margin  somewhat  oblique,  slightly 
concave.  Postero-ventral  angle  rounded.  Umbones  high,  prominent,  not  much 
incurved.  A  jn'oiiiiuent,  rounded  carina  extends  from  the  umbo  to  the  postero- 
ventral  angle,  and  cuts  off  a  posterior  area  which  is  divided  into  two  parts  by  a 
sti'ong,  rounded  carina  ending  at  the  postcro-dorsal  angle.  The  part  of  the  area 
between  the  carinas  is  concave ;  the  part  l^ehind  the  median  carina  is  deeply 
depressed.  Lunule  large,  very  deep,  flattened.  Surface  of  shell  apparently 
smooth.     Length,  48  mm.     Height,  58  mm. 

Affi7iities. — It  is  possible  that  this  species  may  be  related  to  0.  Gallicnnd, 
d'Orbigny,'  which  seems  to  be  known  by  casts  only,  but  tlie  height  of  the  shell 
appears  to  be  relatively  less.  0.  Gallieiuiei  has  been  identified  by  some  authors 
with  0.  hirorii!.'<  (Geinitz)  -  f rom  the  Cenomanian  of  Plauen.  The  latter  differs 
from  the  species  described  above  in  possessing  strong  concentric  ribs  and  in  the 
absence  of  a  carina  between  the  umbo  and  the  postero-ventral  angle. 

h'l'iniirks. — Tlie  only  undoubted  example  of  this  species  which  I  have  seen  is  a 
right  valve  collected  by  the  late  W.  Vicary,  and  now  in  the  British  Museum.  The 
surface  of  the  shell  is  not  well  preserved,  but  appears  to  have  been  nearly  smooth. 

An  imperfect  specimen  of  a  large  Opis  (length  about  (33  mm.)  from  the 
Chloritic  Marl  of  Eggerdon  Hill  (Dorset)  is  in  the  Sedgwick  Museum,  Cambridge, 
and  may  belong  to  this  species. 

Distribtitioit. — Upper  Greensand  (zone  of  Schlfienhachhi  rodnita)  of  Haldon. 


Oris,  sp.     PI.  XVII,  figs.  13  <i-c,  14  <i-c. 

Dcscrijitiui). — Shell  small,  sul)-triangular,  rather  oljlique ;  greatest  convexity 
along  the  carina.  Antei'ior  margin  rounded;  posterior  margin  slightly  convex. 
Umbones  prominent,  sliarp,  considerably  curved  anteriorly.  Carina  sliai'p, 
prominent,  cutting  off  a  steeply  sloping  posterior  area,  which  is  not  divided  by  a 
median  carina.  Sides  of  sliell  flattened,  sloping  slightly  in  front  of  the  carina,  and 
passing  gradually  into  the  anterior  part  of  the  shell.  Lunule  very  deep,  with  a 
sharp  border. 

Ornamentation  consists  of  regular,  concentric  ribs.  Postei-ior  area  nearly 
smooth. 

>  •  Vdl.  Fniiu;.  'iViT.  Civt.,'  vol.  iii  (18-J-t),  pi.  CL-lvii///.s  tii;.  5  (not  tlesfnlH.'d  iu  the  text); 
(ji lu'rauger,  '  Alhuiii  PaK'oiit.  de  la  Sartlio  '  (1867),  p.  17,  pi.  xxii,  fij,'.  13. 

2  "Das  Elhthal^'el).  iu  Sachsen"  ('  Palicoiitographiea,'  vol.xx.  pt.  1,  1873),  p.  227,  pi.  1,  fii^'s.  1—3. 
luterual  casts  of  OjJis  from  the  base  of  the  Chalk  at  Maideu  Newtoii  aiul  Chard  have  beeu  recorded 
as  0.  hiconm?  (Gein.)  by  Jiikes-Browue,  '  Cret.  Eocks  of  Britain,'  vol.  ii  (1903),  pp.  113,  122.  Two 
of  the  specimens  on  which  the  determiuation  was  based  are  in  the  Oxford  Museum. 


CARDITA.  121 

Measurements  : 

(1)  (2) 

Length  .  .  .  8         .  7"o  iiiiii. 

Umbo  to  postero- ventral  angle  .  12         .         ll'O     „ 

(1,  2)  Haldou. 

Affinities. — This  species  may  perhaps  be  related  to  0.  cenomanensis,  Gudranger/ 
but  the  figure  of  the  latter  is  too  indistinct  for  recognition. 

Bemarls. — There  are  four  examples  of  this  species  in  the  Vicary  Collection, 
British  Museum. 

Distribution. — Upper  Greensand  (zone  of  Hrlilimhaclna  rustniln)  of  Haldon. 


i^«m%— CARDITID^,  Uill. 

Genus — Cahdita,  ./.  G.  Bruguiere,  1792." 
('  Encyc.  uii-th.,  Vers,'  vol.  i,  p.  401.) 

CAiiDiTA?  FENESTEATA  (Forbes),  1845.     Plate  XVIII,  figs.  2-4. 

1845.     Ventjs  ?  FENESTEATA,  E.  Forbes.     Quart.  Jouru.  Geol.  Soc,  vol.  i,  p.  240, 

pi.  ii,  fig.  6. 
1850.     Cardita  —  A.  d'Orbigny.     Prodi-,  de  Pal.,  vol.  ii,  p.  77. 

1854.     Venus  —  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  230. 

1856.     Caedita  —  F.  J.  Pidet  and  E.  Renevier.     Foss.  Terr.  Aptieu 

(Mater.  Pal.  Suisse,  ser.  1),  p.  82, 

pi.  is,  fig.  4. 
1866.  —  —  F.J.  Pidet  and  G.  Campidie.     Foss.  Terr.  Crt't.  Stc. 

Croix  (Mater.  Pal.  Suisse,  ser.  4), 

p.  333. 
1871.  —  —  F.  Stoliczlta.     Palseont.  Indica,  Cret.  Faima  S.  India, 

vol.  iii,  p.  287. 

Description. — Shell  oval  or  somewhat  rhomboidal,  much  longer  than  high,  very 
inequilateral,  moderately  inflated,  but  with  flattened  sides.  Anterior  margin 
rounded  ;  ventral  margin  slightly  curved  or  almost  straight,  and  nearly  parallel 
with  the  dorsal  margin;  posterior  margin  obliquely  truncated,  forming  an  acute  angle 

'  '  Album  Pak'ont.  de  la  Sarthe'  (1867),  p.  13,  pi.  xvi,  fig.  3. 

-  Owing  to  the  difficulty  of  distinguishing  the  fossil  forms  of  Cardita  from  Vaicricardia  when,  as 
in  the  case  of  nearly  all  the  examples  found  in  the  Cretaceous  rocks  of  England,  the  hinge  is  unknown, 
all  the  species  are,  for  the  present,  referred  to  Cardita. 

10 


122  CJRKTACEOUS    LAMELLTBRANCHIA. 

with  the  veiiti'al  margin,  and  an  obtuse  angle  with  the  dorsal  margin.  Umbones 
moderately  prominent,  curving  foi'wards,  bearing  a  carina  which  extends  to  the 
postero-ventral  angle  antl  cuts  off  a  flattened  or  concave  area.  Lunule  ovate, 
rather  large,  nearly  smooth.     Escutcheon  with  a  sharp  edge. 

Ornamentation  consists  of  narrow,  rounded,  radial  ribs,  separated  by  broad, 
flat  interspaces,  and  crossed  at  rather  distant  intervals  by  strong,  narrow,  con- 
centric, lamellar  ribs,  which  give  rise  to  a  scale-like  projection  where  they  join 
the  radial  ribs.  The  postero-dorsal  area  has  similar  concentric  ribs,  and  a  strong 
radial  rib  near  the  dorsal  margin,  and  another  near  the  middle  of  the  area  with 
smaller  ribs  between. 


Measurements  : 

W 

(2) 

(3) 

(4) 

(5) 

(6) 

Length 

20 

19 

19 

19 

18 

IG  mm. 

Height 

14 

13 

12 

11-5 

12 

11     „ 

(1 — 6)  Perwa-bed,  Atherfield. 

Affinities. — G.  fenestraia  appears  to  be  quite  distinct  from  other  Cretaceous 
species  of  Cardita,  but  shows  some  resemblance  in  form  to  G.  tricarinata,  d'Orbigny,' 
from  the  Cenomanian  of  Le  Mans.  The  hinge  and  interior  are  unknown,  and  the 
generic  position  of  the  species  is  not  free  from  doubt.  Stoliczka  remarks 
that  '  G.  fenestraia  is  not  unlike  a    Venerupis.' 

Type. — From  Peasmarsh,  in  the  Museum  of  tlie  Geological  Society,  Nos. 
2182,   2183. 

Distribufiun. — I'cnia-Xwd  and  Atherfield  Clay  of  Atherfield.  Atherfield  WeiU 
of  Peasmarsh  and  East  Shalford. 


Cardita  upwarensts,  s]).  nov.     Plate  XVIII,  fig.  5. 

1883.     Cakdita  eotundataV   W.  Keejiincj.     Foss.,  etc.  Ncoe.  Upwarc  aud  Brick- 
hill,  p.  121,  pi.  vi,  tig.  7. 

Description. — Shell  subtriangular,  inflated,  height  and  length  neai'ly  e(|ual, 
inequilateral.  Anterior  margin  i-ounded,  passing,  gradually  into  the  convex  ventral 
margin.  Posterior  margin  truncated,  oblique,  not  sharply  limited  from  the  postero- 
dorsal  margin.     Umbones  prominent,  strongly  curved  anteriorly,  with  a  rounded 

1  '  Pal.  Fran9.  Terr.  Grot.,'  vol.  iii  (1844),  p.  95,  pi.  cclxxxiii  his.,  tigs.  5—7;  Guorauger,  '  Allmiu 
Palcont.  de  la  Sarthe'  (18G7),  p.  13,  pi.  xvi,  figs.  Ifl,  20. 


CARDITA.  123 

carina  extending  to  the  postero-ventral  angle,  and  cutting  off  a  steeply-sloping 
postero-dorsal  part  of  tlie  valve.     Lunule  rather  small,  cordate,  broader  than  long.. 

Ornamentation  consists  of  about  twenty-five  radial  ribs  on  the  part  of  the  valve 
in  front  of  the  carina ;  the  ril)s  are  strong  and  rounded,  but  are  narrower  than 
the  interspaces.  Both  are  crossed  l)y  regular  concentric  lamellre,  which  become 
prominent  on  the  rilis.  On  tlie  postero-dorsal  area  the  ril)S  are  smaller,  more 
numerous,  and  closer  together;  two  of  tliese  ribs  are  rather  stronger  than  the 
others,  and  divide  the  area  into  three  parts.  Length  21  mm.  ;  h(>ight  20-.5  mm.; 
thickness  17  mm. 

Affinities. — This  species  was  doubtfully  referred  by  W.  Keeping  to  C.  rotundafa, 
Pictet  and  Roux,  but  it  differs  from  that  form  by  its  fewer  and  stronger  ribs  and 
more  triangular  outline  (see  p.  125). 

In  form  it  resembles  G.  Dufiniana,  d'Orbigny,^  bi;t  the  ribs  on  the  postero- 
dor.sal  area  are  smaller  and  moi'e  numerous.  In  this  respect,  and  in  its  shorter 
and  less  quadrate  outline,  it  differs  from  G.  neocominins,  d'Orbigny.- 

Remarks. — I  have  seen  only  three  examples  of  this  species,  two  of  which  are  in 
the  Sedgwick  Museum,  and  one  is  in  the  collection  of  Mr.  J.  F.  Walker. 

Distribution. — Lower  Greensand  of  Upware  and  Potton. 


Cardfta,  sp.     Plate  XVIII,  fig.  6. 

A  specimen  consisting  of  the  united  valves  from  which  the  ventral  parts  are 
missing  was  obtained  by  Leckenby  from  the  rerna-hed  of  Atherficld,  and  is  now 
in  the  Sedgwick  Museum.  It  shows  some  resemblance  to  G.  iqnrarensis  (see 
above),  but  is  more  elongate  and  more  distinctly  carinate. 


Cabdita,  sp. 

Two  specimens  of  Garditn  from  the  Hythe  Beds  of  Maidstone  are  in  the  Museinn 
of  the  Geological  Society.  They  were  examined  by  Edward  Forbes,'*  who  identified 
one  with  C.  neocomiensis,  d'Orbigny,  and  the  other  -svith  C.  quadrata,  d'Orljigny. 
The  specimens  are  similar  in  form  to  those  species,  but  their  state  of  preservation 
is  too  imperfect  for  satisfactory  determination. 

1  'Pal.  Franc.  Terr.  Crt't.,'  vol.  iii  (1844),  p.  88,  pi.  cclxviii,  figs.  6— 10;  Pictet  and  Campiche. 
'  Foss.  Terr.  Cret.  Ste.  Croix  '  ('  Mater.  Pal.  Suisse,'  ser.  4,  1866),  p.  334,  pi.  cxxvi,  figs.  4,  5. 
-  D'Orbigny,  ojj.  cit.,  p.  85,  pi.  cclxviii,  figs.  1 — 6. 
3  '  Quart.  Jouru.  Geol.  Soc.,'  vol.  i  (1845),  p.  242. 


124  CRETACEOUS    LAMELLIBRANCHIA. 


Cardita  tenuioosta  (Sowerhy),  1836.     Plate  XVIII,  fi.i^^s.  7-14. 

1836.     Venericardia  tenuicosta.  J.  de  C.  Sowerhy.    Traus.  Geol.  Soc,  ser.  2,  vol. 

iv,  pp.  114,  259,  356,  pi.  xi, 
fig.  7*. 
1838.     Cardium  tetragonum,  H.  Michelin.     Mem.  Soc.  geol.  de  France,  vol.  iii,  p. 

102,  pi.  xii,  fig.  3. 
1842.     Venericardia  teniticosta,  A.  Leymerie.   Mem.  Soc.  geol.  de  France,  ser.  2, 

vol.  V,  p.  25,  pi.  iii,  fig.  0. 
1844.     Cardita  tenuicosta,  A.  (FOrbigny.     Pal.  Fran9.  Terr.  Cret.,  vol.  iii,  p.  87, 

pi.  cclxviii,  figs.  1 — 5. 
1846.     Venericardia  tenuicosta,  A.  Leymerie.     Statist,  geol.  et  min.  de  I'Aubc, 

pi.  V,  fig.  7. 
1850.     Cardita  —  d'Orhigny.     Prodr.  de  Pal,  vol.  ii,  p.  137. 

1854.  —  _  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  191. 

1855.  —  —  G.  Cotteau.     MoU.  Foss.  de  I'Yonne,  p.  72. 
18GG.          —                         —F.J.  Pictet  and  G.  Campiche.   Foss.  Terr.  Cret. 

Ste.  Croix  (Mater.  Pal.  Suisse, 
ser.  4),  p.  335,  pi.  cxxvi,  figs. 
6—9. 
1871.  —  —  F.  Stoliczka.     Paloeont.  Indica,  Cret.  Fauna  S. 

India,  vol.  iii,  p.  287. 

Non  1842.     Venericardia         —  H.  B.  Geinitz.     Char.  d.  Schicht.  u.  Petref.  des 

siiclis.-bohm.  Kreidegeb.,  pt. 
3,  p.  76,  pi.  XX,  fig.  9  (C. 
Geinitzi,  d'Orbigny). 

—  184C.     Cardita  (Venericardia)  tenuicosta,  A.  E.  Reuss.   Die  Versteiu.  der  biJlim. 

Kreideformat.,  pt.  2,  p.  4,  pi. 
xxxiii,  fig.  16  (C  corrugata, 
Eeuss). 

—  1873.     Cardita  tenuicosta,  H.  B.  Geinitz.     Das  Elbtlialgeb.  in  Saclisen  (Palaeon- 

tograpliica,  vol.  xx,  pt.  2),  p.  60, 
pi.  xvii,  figs.  11 — 13. 

—  1885.  —         (Venericardia)  tenuicosta,   F.  Ni'iiliiuj.   Die  Fauna  d.  baltiseli. 

Ceuoman.  (Palseout.  Abhaudl.,  vol. 
ii),  p.  29,  pi.  V,  fig.  4. 

—  1889.  —        tenuicosta,  A.  Fritsch.      Stud,  im  Gebiete  der  bolim.  Kreide- 

format., iv.  Teplitz.  Scliicht.,  p.  78, 
fig.  62. 

—  1893.  —  —  Fritsch.     Titrf  v.  Priesener  Schicht.,  p.  91. 

? —  1900.  —  —  A.  WoUemann.     Die  Biv.  u.  Gastrop.  d.  deutsch.  u. 

hollilud.  Neocoms  (Abhandl.  d. 
k.  preussisch.  geol.  Land.,  N.  F., 
pt.  31),  p.  94,  pi.  iv,  fig.  9. 


CARDITA.  125 

Description. — Shell  more  or  less  sub-quadrate,  rounded,  moderately  convex, 
with  the  postero-dorsal  portion  compressed ;  length  greater  than  height ;  moderately 
inequilateral.  Postero-dorsal  margin  only  slightly  curved;  posterior  margin  more 
or  less  truncated,  passing  by  a  regular  curve  into  the  ventral  margin,  which  is  only 
slightly  convex  and  nearly  parallel  with  the  postero-dorsal  margin.  Anterior 
margin  roimded.  Antero-dorsal  margin  concave.  Umbones  curved  anteriorly. 
Lunule  ovate,  nearly  smooth.     Escutcheon  lanceolate,  with  a  sharp  edge. 

Ornamentation  consists  of  47  to  57  rounded  radial  ribs,  which  are  separated 
by  furrows  of  greater  breadth  than  themselves ;  near  the  postero-dorsal  margin 
these  ribs  are  rather  closer  together  than  elsewhere.  In  some  cases  the  postero- 
dorsal  part  of  the  valve  is  divided  into  two  parts  by  two  ribs,  which  are  more 
prominent  than  the  others.  At  regular  intervals  concentric  lamellse  occur  and  form 
marked  projections  where  they  cross  the  ribs.  Near  the  umbo  these  lamellfe  are 
more  widely  separated,  and  near  the  margin,  especially  in  large  specimens,  they 
are  closer  together  than  elsewhere.  Sometimes  faintly  marked  concentric  ridges 
may  be  seen  on  the  ribs  between  the  lamellae.     Margins  of  valves  crenulate. 

Measurements  .- 

(1)  (2)        (3)        (4)       (5)  ((i)  (7) 

Length  .     30       27     25     24     24     23-5     28 
Height  .     26-5    23     22     22     20     21        21 

(1—14)  Gault,  Folkestone. 

Affinities. — This  species  has  more  numerous  ribs  and  is  less  inflated  than 
C.  neocomiensis,  d'Orbigny  and  G.  Diqiini'ina,  d'Orbigny.i  It  possesses  about  the 
same  number  of  ribs  as  G.  Gonstanti,  d'Orbigny,-  but  is  less  elongate  and  less 
inflated.  G.  rotundata,  Pictet  and  Roux,^  differs  from  G.  tenuicosta  in  being 
more  inflated,  and  can  be  regarded  as  only  an  individual  variation.  Some  examples 
found  at  Folkestone,  which  in  other  respects  agree  with  G.  temoicosta,  are  as  much 
inflated  as  the  type  of  G.  rotundata.  G.  dathrata,  Buvignier,*  is  a  small  form,  but 
has  the  concentric  laminae  more  widely  separated  than  in  even  the  young  of 
G.  tenuicosta.  G.  argonneiisis,  Buvignier,^  is  more  compressed  and  has  more  slender 
ribs  than  G.  tenuicosta.  G.  cenomanensis,  d'Orbigny,"  is  distinguished  from 
G.  tenuicosta  by  its  broader   ribs   and   more   closely  placed  concentric  lamellae. 

G.  temoicosta  has  narrower  ribs  and  broader  furrows  than  the  forms  from  the  Chalk 

1  For  references  to  figures  of  these  species  see  p.  123,  footnotes  1,  2. 

2  '  Pal.  Fran9.  Terr.  Cret.,*  vol.  iii  (1844),  p.  89,  pi.  cclxix,  figs.  1—5 ;  Pictet  and  Campiche, '  Foss 
Terr.  Crct.  Ste.  Croix'  ('Mater.  Pal.  Suisse,'  ser.  4,  1866),  p.  337,  pi.  cxxvi,  fig.  10. 

3  '  Moll.  Foss.  Grcs  verts  de  Geneve'  (1852),  p.  443,  pi.  xxxiii,  tig.  6. 

*  '  Statist,  geol.,  etc.,  de  la  Meuse,'  Atlas  (1852),  p.  19,  pi.  xv,  figs.  16,  17. 

5  Ibid.,  p.  19,  pi.  xxxii,  figs.  1 — 3. 

«  D'Orbigny,  op.  cit.,  p.  94,  pi.  cclxxxiii  bis.,  figs.  1  -4. 


(8)   (9) 

(10) 

(H) 

(12)   (13) 

(14) 

23  22 

22 

20 

16  15 

15  mm 

19-5  20 

19 

17 

14-5  14 

13  „ 

126  CRETACEOUS   LA]\rELLIBRAXCHIA. 

of  Saxony  and  Bohemia  wliicli  have  Ijoen  referred  to  that  species  by  Geinitz  and 
by  Renss.  C  icnuicosta  of  Reuss  is  the  type  of  G.  (Venencardia)  bohemica, 
Griepenkerl.^ 

B,emarlvS. — Numerous  specimens  of  C.  tennicosta  from  Folkestone  have  been 
examined,  and  they  are  found  to  show  a  considcralile  amount  of  variation  in  con- 
vexit}'  and  in  relative  height  and  length. 

Type. — The  type  came  from  the  Gault  of  Folkestone,  but  cannot  now  be  found. 

Distribution. — Gault  (zones  i,  v,  vii,  viii,  ix,  xi)  of  Folkestone.  Recorded  by 
Jukes-Browne  from  the  Cambridge  Grcensand,  and  l)y  Barrois  fiom  the  Upper 
Greensand  (zone  of  Schlanibachia  rostrata)  of  the  Isle  of  Wight. 


CAiiiniA  CoTTAMnNA,  (VOrhhjnij,  184-i.     Plate  XVIII,  figs.  15,  IG. 

1844.     Caedita  Cottaldina,  A.  d'Orhignij.     Pal.  Fran9.  Terr.  Cret.,  vol.  iii,  p.  01, 

pi.  celxix,  figs.  6 — 8. 
1871.  —  —  F.  Stoliczlca.     Palseont.  Indica,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  287. 
?  1895.  —        c/.  Cottaldina,  i/.  T/essCTi.   Zeitsclir.  der  deutscli.  geol.  Gesellscli., 

vol.  xlvii,  p.  485. 

Bemarlis. — Examples  of  a  species  of  Gardita,  which  is  not  uncommon  in  the 
Chloritic  Marl  of  Dorset,  appear  to  belong  to  G.  Gottaldina,  but  their  state  of 
preservation  is  very  unsatisfactory.  Most  of  the  specimens  are  internal  casts,  and 
in  cases  where  parts  of  the  shell  are  present  the  surface  is  very  imperfect,  so  that 
the  characters  of  the  ornamentation  cannot  be  clearly  distinguished.  M.  Raoul 
Fortin  informs  me  that  the  preservation  is  equally  unsatisfactory  in  the  Cenomanian 
of  Rouen,  from  whence  d'Orbigny's  specimens  were  obtained. 

The  shell  is  quadrate  in  outline,  very  convex,  carinate,  and  somewhat  longer 
than  high.  The  ornamentation  appears  to  consist  of  about  40  ribs,  separated  by 
interspaces  of  great  width. 

G.  Gottaldina  may  be  distinguished  from  G.  tennicosta  (p.  124)  by  its  fewer  ribs, 
by  the  length  and  height  being  more  nearly  equal,  and  by  the  greater  convexity  of 
the  valves. 

Measurements  ; 

(1)  (2)  (3) 

Length      .  .         21         .         20         .         16-5  mm. 

Height      .         .         19         .         18         .         14       „ 
Thickness  .         16  l.r5      .         12       „ 

(1—3)  Chloritic  Marl.     (1)  Chaldon,  (2)  Chard,  (3)  Balcombe. 
1  '  Palseont.  Abhandl.,'  vol.  iv  (1889),  p.  58. 


CARDITA.  127 

Distribution. — Chloritic  Marl  of  Balcombe,  Cerne,  Chaldon,  Clialmingtoii,  Cliard, 
Maiden  Bradle}',  and  Maiden  Newton.  Recorded  by  Jukes-Browne  from  the 
Chloritic  Marl  and  the  zone  of  Schlocnbachia  carians  of  the  Isle  of  Wi"-ht. 


Cardita,  sp. 

Specimens  of  (Jiirildn  from  which  the  shell  has  disappeared,  but  showing  traces 
of  the  ribs,  are  found  in  the  Chalk  Marl  of  Ventnor,  Folkestone,  etc.  These  are 
too  imperfect  for  specific  determination.  A  specimen  from  Riugmer  was  figured 
by  Sowerby,^  and  was  subsequently  regarded  by  d'Orbigny-  as  an  example  of  his 
G.  ditbia. 

Somewhat  similar  specimens  also  occur  in  the  Upper  Greensand  of  Devizes. 


Cardita  cancellata,  Woods,  1897.     Plate  XVIII,  figs.  17,  18. 

1897.     Cardita  cancellata,  H.  Woods.     Quart.  Jouru.  Geol.  Soc,  vul.  liii,  p.  390 

pi.  xxviii,  tigs.  2 — 5. 

Description. — Shell  oval,  slightly  inequilateral,  inflated,  postero-dorsal  part 
compressed,  faintly  carinate;  length  rather  greater  than  height;  margins  rounded. 
Umbones  moderately  prominent,  curved  anteriorly. 

Ornamentation  consists  of  a  large  number  of  radial  ribs  sepai^ated  l)y  narrow 
furrows,  and  crossed  l)y  numerous  concentric  ribs,  giving  a  nodular  appearance  at 
the  points  of  intersection.  The  concentric  ribs  are  moi'c  distinct  on  the  anterior 
part  and  the  radial  ribs  more  distinct  on  the  median  and  posterior  parts  of  the 
shell.     Margin  of  valves  finely  crenulate. 

Measurements  .- 

(1)  (2)  (3) 

Length         .         18         .         16         .         13  mm. 
Height         .         16         .         14-5      .         12    „ 
(1 — 3)  Chalk  Kock,  Cuckhamsley. 

Ajjiinfies. — This  species  is  more  inflated  and  more  rounded  than  G.  tcnuicusla 
(p.  121),  and  possesses  more  numerous  radial  riljs  with  narroAV  furrows  and 
strong  concentric  ribs  instead  of  lamina?. 

The   concentric  ribs   distinguish   G.   cancellata    fi'oni   the  forms  desci-il)ed  by 

1  '  Mill.  Couch.,'  vol.  iii  (1820),  p.  106,  pi.  cclix,  fij;.  3  (the  orighiul  is  now  in  the  Britisli  Musoiim). 
Venericardia'i  Maiitell,  '  Foss.  S.  Dowiis'  (1822),  p.  12»->. 

2  'Pal.  Fraiiv-  Terr.  Cn't.,'  vol.  iii  (18-44),  p.  92,  pi.  cclxx,  H^s.  1—5.  Uiu-rau-er,  •  .Ubuni 
Palcoiit.  de  la  Sarthe'  (18(37),  p.  13,  pi.  xvi,  tigs.  14—18. 


128  CRETACEOUS   LAMELLIBRANCHIA. 

Geinitz  ^  and  by  Reuss  ^  as  C.  tenuicosta.  The  concentric  ribs  and  the  nodular 
character  which  they  give  to  the  radial  ribs  separate  G.  cancellata  from  Veneiicardia 
santoncnsis,  Miiller.'' 

llemarlcs. — The  specimens  of  C^.  cancdlata  are  chiefly  in  the  form  of  internal 
and  external  moulds ;  wax  casts  of  the  latter  show  the  character  of  the  ornamenta- 
tion.    In  a  few  cases  small  portions  of  the  shell  are  still  preserved. 

Type. — From  the  Chalk  Rock  of  Cuckhamsley,  in  the  Sedgwick  Museum. 

Distribution. — Chalk  Rock  of  Cuckhamsley,  Aston  Hill,  Chinnor  Hill,  Thick- 
thorn  Hill  (Bledlow),  Boxnioor,  Luton,  and  Wood  Ditton. 


J'timiVv/— CRASSATELLITID^,  X»a«. 

Gemis — Crassatbllites,  /.  F.  Kriiger,  1823. 
('  Geschichte  d.  TJrwelt.,'  ii,  p.  466.) 

Ckassatellites  DivisiENSis,  sp.  uov.     Plate  XIX,  fig.  1. 

Description. — Shell  subquadrate,  very  inequilateral,  moderately  long,  convex, 
but  with  flattened  sides,  carinate.  Anterior  margin  regularly  rounded  ;  ventral 
margin  nearly  straight,  oblique  to  the  postero-dorsal  margin ;  posterior  margin 
convex,  oblique,  forming  an  obtuse  angle  with  the  postero-dorsal  margin,  which  is 
nearly  straight.  TJmbones  rather  prominent,  curved  anteriorly.  Carina  rounded, 
forming  a  gentle  curve  between  the  umbo  and  the  postei'O-ventral  angle. 
Posterior  area  moderately  large,  apparently  not  divided  by  a  median  rib.  Lunule 
deep. 

Ornamentation  consists  of  numerous,  strong,  regular,  concentric  ribs,  separated 
by  shallow  furrows.  On  the  posterior  area  the  ribs  appear  to  be  narrower. 
Length  45  mm. ;  height  37  mm. 

Affinities. — This  species  shows  some  resemblance  to  G.  Guerangeri,  d'Orbigny,* 

1  C.  Geinitzii,  cVOrbiguy,  '  Proclr.  Je  Pal.,'  vol.  ii  (1850),  p.  239.  For  references  to  Geinitz's 
figures  see  above  (p.  1'24). 

~  '  Die  Verstein.  der  bohm.  Kreidefomiat.,'  pt.  2  (184-6),  p.  4,  pi.  xxxiii,  fig.  16.  C.  corrngata, 
Ecuss,  '  Geogu.  Skizzen  aus  Biilimeu,'  vol.  ii  (1844),  p.  I'JO  ;  Giiiiibel, '  Alilmudl.  d.  k.  bayeriscli.  Akad.' 
(Miiuclieu),  vol.  x  (1868),  p.  568.  Canlita  {Venericardia)  boheinica,  Grit'peiikerl,  '  Seiiou.  KiJuigs- 
lutter'  ('Palaeont.  Abhandl.,'  vol.  iv,  1889),  p.  58.  See  also  C.  Cottaldina,  i'Orhigny,  '  Vrodr.  da 
Pal.,'  vol.  ii  (1850),  p.  161. 

•■'  '  MoUusk.  Unterseu.  v.  Braunschweig  u.  Ilsede '  (1898),  p.  55,  pi.  vii,  tigs.  10—12. 

*  'Pal.  Frau9.  Terr.  Crct.,'  vol.  iii  (1844),  p.  76,  pi.  cclxv,  figs.  1,2;  Gucranger,  'Album  Pak'ont. 
de  la  Sartlie'  (1867),  p.  13,  pi.  xvi,  fig.  11. 


CRAS8ATKLLITES.  12<) 

Init  is  iiKiiv  iii(M|iiilat('i-iil,  the  ventral  margin  is  nearly  straight,  llie  posterior 
mai'giii  is  more  obliqne,  and  the  posterior  area  is  relatively  smaller.  It  is  much 
more  inequilateral  than  ('.  regularis,  d'0rbign3^^  C.  divifiiensi.s  also  resembles 
some  of  the  varieties  of  C.  macrodonta  (Sowerby)-  from  Gosaii. 

Distribution. — Upper  Greensand  (zone  of  Sclilmnhacliia  roxtrata)  of  Devizes. 
An  imperfect  specimen  from  Warminster  (zone  of  Pecten  asjier)  probably  belongs 
to  this  species. 


Ci!AssATi:rj,iTE8  viXDiNNENSis  {d' Orhif/mj),  1844.     Plate  XIX,  figs.  2,  o. 

1844.     Crassatella  vindinnensis,  A.  d'Oihiijuy.     Pal.  Fran^.  Terr.  Cri't.,  vol.  iii, 

ji.  79,  pi.  cclxvi,  figs.  1 — 3. 
1850.  —  vENDiNNENSis,  d'Orbigtiij.     Prodr.  tie  Pal.,  vol.  ii,  p.  160. 

1867.  —  VINDINNENSIS,  E.  Gurnviger.     Album  Pali'ont.  de  la  Saribc, 

p.  13,  pi.  \vi,  figs.  9,  10. 
?  1868.  —  —  C.  W.  Giimbel.     Geo<^u.  Beschreib.  Ki'migreicbs 

Bajern,  vol.  ii,  p.  766. 
1871.  —  —  F.  Sloliczka.     PalBeont.  Iiidica,  Cret.  Fauna  S. 

India,  vol.  iii,  p.  294. 

Deserijitiun. — Sliell  sulKpiadrate,  bnt  trigonal  without  the  posterior  area,  very 
inequilateral,  convex,  with  rounded  carina.  Anterior  margin  rounded,  passing 
gradually  into  the  slightly  curved  ventral  margin ;  posterior  margin  oblique,  some- 
what sinuous ;  postero-dorsal  margin  nearly  straight,  forming  an  obtuse  angle  with 
the  posterior  margin.  Lunule  elongate,  deep.  Uml)ones  prominent,  incurved. 
Posterior  area  of  moderate  size,  divided  by  a  median  rib  into  two  parts,  of  which 
the  anterior  is  concave. 

Ornamentation  consists  of  strong,  regular,  concentric  ribs,  separated  l^y  narrow 
fnrrows.  On  the  posterior  area  the  ribs  become  very  narrow  and  more  or  less 
lamellar,  and  the  interspaces  are  broad  and  flat. 

Measurements  : 

(1)  (2) 

Length    ...         31  ..         30  mm. 

Height    .         .         .         26  .         .         20     „ 

(1,  2)  Duuscombe. 
Ajfiiiitirs. — This  s]iccie.s  is  related  to  ('.  Iltirrifiisis,  d'Oi-i)igny,-'  and  ('.  (luvraii- 

'  Op.  cit.,  p.  80,  pi.  cclxvi,  figs.  4 — 7. 

2  Zittd,  "Bivalv.  d.  Gosaugeb."  (' Denkschr.  d.  k.  .Akad.  Wien,  Matli.-Nat.  CI.,'  vol.  xxv,  pt.  2, 
1866),  p.  150,  pi.  viii,  figs.  2,  3. 

^  '  Pal.  Fi-an9.  Terr.  Crct.,'  vol.  iii  (1844),  p.  77.  pi.  cclxv,  figs.  3—5  ;  Guurauger, '  Album  Pali'out. 
de  la  Sarthe'  (1867).  \k  13,  ].l.  xvi,  fig.  12. 

17 


]:;(i  ("RKTACEOIIS    LAMEI.I.I  HIIANCHIA. 

gerl,  d'Urbignv,'  but  the  [JostciMoi'  inarii'in  is  more  (ilili(|ni'  ami  the  ])i)st(_MMoi'  ai'ca 
relatively  .smaller. 

Bcmarlra. — The  lamellar  I'ilis  on  the  postei'iur  area  are  not  mentioned  l)y 
(rOi'l)iu,ny,   but  attention   is  ealled   to  them  by   (Juerauger. 

I  have  seen  only  five  specimens,  which  were  collected  l)y  the  late  ('..).  A.  Mej'er, 
and  are  now  in  the  Sedgwick  Museum,  Cambridge. 

G.  v'mdinnensis  is  the  type  of  Conrad's-  genus  I'lichi/lluents. 

Types. — Fi'om  the  Cenomanian  of  Rouen  and  Le  Mans. 

Dislributlun. — Cenomanian  (Meyer's  Beds  10  and  12)  of  Duuscombe,  Devon. 


Cu'iiitfi — Anthonya,  ir.  M.  iliihh,  18G4. 

(•  Geol.  Siirv.  Ciiliroruia,  Pateout.,'  vol.  i,  ji.  181,  pi.  xxx,  iig.  2;i().) 

Antiiony.\  ('.\ni'i.\x.\,  sp.  nov.     Plate  XIX,  figs.  4,  5. 

hcxcriptinii. — Shell  elongate,  tajiering  posteritM'ly,  very  inei|uilateral,  much 
eoiupressed.  Anterior  margin  slightly  convex.  Ventral  margin  long,  moderately 
convex.  Posterior  margin  short,  truncate,  forming  angles  with  the  ventral  and 
dorsal  margins.  Postero-dorsal  margin  concave.  Umbones  acute,  near  the  antei'ior 
end.  A  faint  carina  passes  from  the  umbo  to  the  postero-ventral  angle  and  cuts 
off  a  flattened  or  slightly  concave  postero-dorsal  area. 

Ornamentation  consists  of  numerous  narrow,  regular,  concentric  ribs  over  the 
whole  surface  of  the  shell.  The  riljs  are  separated  by  furrows  of  greater  width 
than  themselves. 

Measurements  : 

(I)  (2) 

Length    .  .  .         34         .         .         -7  mm. 

Height    .  .         .         27         .  .  14    „ 

(1,  2)  Folkfstoue  Beils,  near  Coiil  Pdiiit. 

Alii  nil  Irs. — This  specie's  is  distinguished  from  .1.  ( 'uniiu'liiniii  ((r()rbigny)'M)y 
the  shorter  anterior  [larl  of  the  sliell,  the  smallei-  apical  angle,  and  by  the  i-ibs, 
wliicli  ai-e  of  v(\\\:\]  or  nearly  eipial  strength  over  the  wliole  surface.  It  is  le.ss 
elongati'  and  has  a  siunller  a[)ical  angle  than  tlie  type  species  A.  etdlrijonitis,  Cabb. 

1  Oj).  cit.,  p.  76,  pi.  cclxv,  figs.  1,  2;  Gucrangcr,  op.  cil..  p.  I'h  pi.  xvi,  fig.  11. 

-  'Amer.  Jouru.  Couch.,'  vol.  v  (1869),  p.  47. 

3  'Pal.  Frau?.  Terr.  Cret.,'  vol.  iii  (1844),  p.  74,  pi.  cclxiv,  figs.  7—9  ;  referrt-d  to  I'ti/choniija  by 
Pictet  aud  Campiclie,  '  Terr.  Grot.  St«.  Croix '  ('  Mati'r.  Pal.  Suisse,"  ser.  4,  1866),  p.  357  ;  E.  G.  Skeat 
ami  V.  Madson,  "Jiir.  Neoc.  and  Gault  Boulder.s  in  Denmark"  (' Dan  marks  geol.  Undersiig.,'  vol.  ii, 
No.  8,  1898),  p.  178,  pi.  vi,  fig.  13. 


CYi'lUNA.  l:«I 

Hcutdrlis. — Only  two  .speciiiicns  have  been  seen,  hulli    of   wliirli   were  collected 
by  Mr.  H.  Keeping,  and  aic  now  in  tlie  Sedgwick  Museum,  Cambridge. 
Dlxtribiit'wit. — Folkestone  Heds,  near  (Vipt  Toint,  Folkestone. 


Anthonya,  sp.     Plate  XIX,  fig.  (3. 

IJescr'qitinii. — Shell  elongate,  tapering  posteriorly,  veiy  incijiulatei'al,  greatlv 
compressed.  Anterior  margin  convex,  rounded,  passing  gradually  into  the  slightly 
curved  ventral  margin.  Posterior  margin  short,  truncate,  forming  angles  with  the 
ventral  and  dorsal  margins.  Postero-dorsal  margin  long,  slightly  concave.  Umbones 
sharp,  anterior.  Carina  indistinct.  Postero-dorsal  area  narrow.  Surface  of  shell 
smooth,  except  for  growth-lines,  which  are  rather  more  distinct  near  the  anterior 
margin  than  elsewhere. 

Length,  38  mm.     Height,  15  mm. 

Ajjiiiificti. — This  species  appears  to  be  closely  allied  to  A.  CornueHaiia  (d'Orbigny),' 
but  does  not  possess  the  concentric  ribs  near  the  anterior  margin.  It  diifers  from 
^4.  cantiana,  sp.  nov.,  in  the  greater  length  of  the  anterior  part  of  the  shell,  the 
greater  curvature  of  the  anterior  margin,  the  lai-ger  apical  angle,  and  the  absence 
of  concentric  ribs. 

Remarks. — A  left  valve  is  the  only  specimen  seen. 

Distribution. — Lower  Greensand  (Crackers)  of  Athcrficld. 


Familu-CYPRimDA],  LnmnrL: 

Genus — Cvi'iMNA,  Laninrcl-,  1818. 
('  Auiin.  situs  Vert.,'  vol.  v,  p.  550) 

Cvi'KiNA  Saussuki  [l!niii(jiiii(rl),  ISlil.     i'late  XIX,  figs.  7 — lo. 

1821.     DoNACiTES  Saussuki,  a.  Brongniarl.     Auu.  ik's  Mines,  vol.  vi,  \t.   655,  pi. 

vii,    fig.    5   (uou   Venus  Haiitsurii, 
Goldfuss,  1840J. 
1854.     Mactra  saussuki,  E.  liencvier.     Mi'ni.  ^'i-ol.  sur  la  Perte-ilii-KIione,  p.  24. 
185(5.     Ctpiuna  Saussuiu,  F.  J.    Piclcl   and   E.    lienevier.      Foss.   Terr.   Aptieu 

(Mater  Pal.  Suisse, 
ser.  1),  \i.  73,  pi. 
viii,  tigs.  1 — 2. 


For  references  see  p.  130,  footuoto  3. 


l:!2  ("RKTACEOUS  LAMELUBILXNCIHA. 

18(55.     Cyprina  Saussuki,  F.  J.  Pirhl  (uid  G.  Camp'n-he.      Foss.  Terr.  Cri't.  Ste. 

Croix  (Matter.  Pal. 
Suisse,  ser.  4),  p. 
220. 
—  —  —  11.  t'uqinnid.     Moll.  Aptifii  do  I'Espagne,  p.  113. 

Tk't>crij)tio)i.'-  Shell  ii.-^nally  <if  siniill  or  moderate  size,  snb-triangulur,  roniHled, 
often  cyreniforni,  convex,  more  or  less  eonsideniLly  inequilateral.  T/iinulai-  iuai\oin 
of  moderate  length,  concave.  Anterior  margin  regularly  rounded,  passing  gradu- 
ally into  tlie  convex  ventral  margin.  Posterior  margin  short,  often  more  or  less 
rounded,  sometimes  truncate,  forming  an  angle  with  the  vential  margin,  and  not 
sharjily  limited  from  the  long  postero-dorsal  margin.  Umbones  pi'diuinent,  l)i-(iad. 
Carina  rounded,  sometimes  rather  indistinct.  Postero-dorsal  area  nariow. 
Lunular  region  deep,  indistinctly  limited.  Escutcheon  elongate,  bounded  by  an 
inconspicuous  carina.  Hinge  not  seen.  Oi-nanientation  consists  of  grcnvth-lines 
and  numerous  minute  radial  ribs. 

Measurement!:! ; 


(1) 

{■2)       (:i)         (1.)         (5)       (0)       (7) 

(H) 

(9) 

Length 

52 

49     40     38-5     38     33     20 

2.')-r, 

21  mm. 

Height     . 

■10 

40     31     33        31     27     21 

21-5 

11)     „ 

Thickness 

34 

31     27     2G                20     10 

(1,  2)   PeniaA,M,  Atherfiekl. 
(3— S))  Crackers,  Atherfield. 

l-l'    „ 

All'niUies. — This  species  is  related  to  C.  nuiaild  (see  ]>.  13  1),  but  the  outline  of 
the  .shell  is  less  distinctly  triangular,  the  sides  are  less  flattened,  the  ventral  margin 
is  moi'e  convex,  the  und)ones  are  broader  and  not  so  high,  the  lunular  mai'gin  is 
not  so  long,  and  the  carina  is  less  distinct. 

ReDuirkfi. — The  relative  height  and  length  of  the  shell,  and  cunse(iuently  the 
outline,  vary  considerably. 

Much  larger  and  more  globose  specimens  (Plate  Xl.X,  fig.  1;'>)  in  which  the 
carina  is  indistinct,  are  associated  with  the  normal  forms  of  ('.  SuKssiiri,  liut  are 
less  abundant.  At  first  sight,  especially  w  hen  the  shell  is  not  (piile  ])i'rl'ect,  lhe.se 
appear  to  be  distinct  from  ('.  Saiifisuri,  but  after  compai'ing  a  number  of  speci- 
mens 1  am  led  to  the  conclusion  that  they  are  only  old  individuals  Avhich  have 
attained  a  large  size. 

Examples  of  C  Sanssnri  from  Atherfield  were  idt'utified  by  I'ictet  and 
C'am|iiche,  but,  hitherto,  no  record  of  the  species  a[i|>ears  to  have  been  made  by 
any  English  writer. 

Ti/2)e. — From  the  Aptian  of  the  Perte-du-Rhone. 

Plsfrihiifiint. — Lower  (livensand  {J'crii(i-])Ci]  and  Crackei's)  of  At  hertield. 
Atherlield  Beds  of  llaslemere  and  lledhill. 


palcxontooraphical  Socict\^,   1007. 


A     MONO  (I  RAP  H 


OF    THE 


CRETACEOUS    LAMELLIBliANCHIA 


OF 


ENGLAND. 


BY 


HENEY  WOODS,  M.A. 

UNIVBBSITT    LECTUBEE    IN    PAL^IOZOOLOOT,   CAMBRIDGE. 


VOL.  II.     PART  IV. 

CYPRINID7E,  ISOCAEDHDJ:,  LUCINIDtE,  CORBID/E,   IMCAIIDIIDI'; 
TELLINIDiE,    MACTRID/E,    AND   YENERID^. 

Pages  133—180;   Plates  XX— XXVII. 


LONDON: 

PRINTED     FOR     THE     PAL^ONTOGRA  PHICAL    SOCIETY. 

1907. 


FKINTED  BT  ADLARD  AND  SON,  LONDON  AND  DORKING. 


CYPRINA.  133 


CvnjTXA  SKDdwicKT  (Wallrr),  18(;(;.     Plate  XIX,  fi^'.  14.     Plate  XX,  figs.  1-5. 

186C.     Sph^ra  Sedgwickii,  ,7.  F.   WnUer.      Ann.  Mag.  Nat.  Hist.,  ser.  3,  vol. 

xviii,  p.  380,  j>l.  xiii,  figs.  1,  2. 
1867.     CvPEiNA  ANGULATA,  var.,  JT.  G.  Seelcy.     Ibid.,  ser.  3,  vol.  xx,  p.  27. 
1875.  —        Sedgwickii,    W.    Kcephuj  in   T.  G.   Bouncy.      •  Cambridgosliiro 

Geology,' p.  68. 
1883.  —  —  W.  Keeping.     Foss.,  etc.,  Neoc.  Upwarc  and  Brick- 

hill,  p.  123,  pi.  vi,  fig.  12. 

Description. —  Shell  more  or  lef?.'?  oval,  sometimes  suli-triangiilar, rounded,  inflated, 
slightly  or  moderately  inequilateral ;  length  as  a  rule  not  greatly  exceeding  the 
height.  Lunular  margin  of  moderate  length,  concave.  Anterior  margin  rounded, 
passing  gradually  into  the  convex  ventral  margin.  Postero-dorsal  margin  moderately 
convex.  Umbones  prominent,  l)road,  curved  inward  and  forward.  Carina  absent 
or  indistinct.  Postero-dorsal  region  convex,  rounded.  Lunule  large,  ovate, 
bounded  by  a  faint  groove.  Escutcheon  long,  bounded  by  a  more  or  less  distinrf 
carina.     Ornamentation  consists  of  growth-lines. 


Meafivrcments 


(1) 

(2) 

(3) 

(1) 

(5) 

(C) 

(7) 

(S) 

(9) 

Length     . 

3!) 

38 

37 

37 

34 

32 

31 

27 

23  mm 

Height     . 

34 

31 

31 

32 

31 

26-5 

27 

21- 

20     „ 

Thickness 

29 

25 

26-5 

23 

24 

JJ 

(1 — 9)  Lower  Greensand,  Upware. 

Affinities. — This  species  is  closely  related  to,  and  may  perhaps  be  only  a  local 
variety  of  G.  Sanssuri  (see  above).  The  chief  points  in  which  it  differs  from  the 
latter  are  (1)  the  carina  is  absent  or  indistinct,  (2)  the  posterior  margin  is 
relatively  higher,  (3)  the  valves  are  usually  more  inflated,  (4)  the  shell  is  usually 
less  triangular  in  outline  and  less  inequilateral. 

RemarliS. — The  examples  of  C.  Se(tgn-irl-i  vary  in  relative  height  and  length, 
and  consequently  in  outline.  The  longer  forms  approach  C.  Savssiiri  more  nearly 
than  the  shorter  forms. 

This  species  was  placed  in  the  genus  Spha-ni  by  '^\v.  .1.  F.  Walker,  l)ut  was 
subsequently  referred  to  Gijimiia  by  Seeley  and  by  "W.  Keeping. 

Type. — From  Potton,  in  Mr.  J.  F.  Walker's  collection. 

Distnhutio)). — Lower  Greensand  of  Upware  and  Potton. 

rvrRiXA  oi'.xrs.v,  Kerpiurj,  1883.     Plate  XX,  fig.  <>. 

1883.     Cyprina  outusa,  TT.  Keepimj.     Foss.,  etc.,  Neoc.  Upware  and  Brickhill.  p. 

124,  pi.  vi,  fig.  13. 

18 


134  CRETACEOUS   LAMELLTBRANCHTA. 

licmnrls. — G.  i>htusa,  ot"  which  I  have  seen  two  specimens  only,  close!}'  re- 
sembles some  forms  of  C.  Saussuri,  but  differs  in  having  narrower  and  less  curved 
umbones.     It  also  resembles  the  more  elongate  forms  of  G.  Sechjunclii. 

Type. — In  the  Sedgwick  Museum. 

Distrihntion. — LoAver  Greensand  of  Upwarc. 


CvrKiNA  rrxEATA,  Smrrrh/,  183C.     Plate  XX,  figs.  7-12. 

1836.     Cyprina  ctjneata,  .7.  de  C.  Sowerhy.     Traus.  Geol.  Soc,  ser.  2,  vol.  iv,  pp. 

240,  341,  pi.  xvi,  fig.  19. 

1849.  —       TRIANGULARIS,  T.  Browii.     Foss.  Couch.,  p.  207,  pi.  Ixxxv,  fig.  2. 

1850.  —       CUNEATA,  A.  (VOrhigny.     Prodr.  de  Pal.,  vol.  ii,  p.  161. 
1854.           —  —J.  Morrh.     Cat.  Brit.  Foss.,  ed.  2,  p.  199. 

1865.  -  —         F  J.  Pictet  and  G.  Canqnche.      Foss.  Terr.  Cri't.  Sto. 

Croix   (Matrr.   Pal. 

Suisse,    ser.    4)    ]>. 

230. 
1870.  —  —         F.  Stoliczlca.     Palasout.   Indica,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  193  [^Anisocardia  {Veni€Ua)'\. 

Descripf ion . — Shell  of  small  or  moderate  size,  triangular,  convex  with  flattened 
sides,  carinate,  considerably  inequilateral.  Lunular  margin  long,  concave.  Anterior 
margin  regularly  rounded.  Ventral  margin  only  slightly  curved,  sometimes 
with  the  posterior  part  concave.  Posterior  margin  short,  truncated,  almost 
straight,  nearly  parallel  to  the  height  of  the  .shell,  forming  a  right  angle  with 
the  ventral  margin  and  an  obtuse  angle  with  the  long  postero-dorsal  mai-gin. 
Umbones  prominent,  high,  curved  considerably  inward  and  forward.  A  distinct,  but 
rounded,  carina  extends  in  a  gentle  curve  fi'om  the  umbo  to  the  postero-ventral 
angle.  In  front  of  the  carina  the  shell  is  sometimes  slightly  concave.  Postero- 
dorsal  area  narrow,  sloping  steeply  except  near  the  posterior  margin.  Lunular 
region  deep,  indistinctly  limited.  Escutcheon  elongate,  lioundcd  by  a  small  carina. 
Ornamentation  consists  of  very  fine  growth-lines  at  regular  intervals. 

Mraanrcments  : 

(1)        (2)         (3)         (4)         (5)  (G)  (7)  (.S)  (9)        (ID) 

Length     .     48     3G     35     31     29     26-5     26     26       23     20  mm. 
Height      .     40     29     29     26     24     20-5     21     19-5    20     16     „ 

(1—10)  Blackdown. 

Affiniflrs. — The  differences  between  C.  Saiisnurl  and  this  species  are  given 
above  (p.  132). 

The  form  from  the  Meule  de  Bracquegnies  which  wiu-^  referred  to  0.  inii'/iiJii/it, 


CYPRINA.  1:55 

Sowc-Hiy,  l)y  Briart  and  Comet,  '  appears  to  he  more  neaily  related  to  C.  cuneata 
than  to  C.  uiKjidala. 

G.  securiformis,  Sluirpe,  -  is  similar  to  C.  cuneata,  but  its  ventral  niar-'in  has  a 
nmeli  greater  cin-vature. 

C.  cuneata  is  mentioned  by  Stoliczka  as  a  typical  example  of  tlie  sub-genus 
Veniella,  Stoliczka.  ^  The  anterior  right  cardnial  tooth,  however,  does  not  appear 
to  bo  so  strongly  developed  as  in  the  type  of  VcidcUa. 

Ttjpes. — The  types  came  from  Blackdown,  but  cannot  now  be  found. 

Distribution. — Upper  Greensand  (zone  of  Schlu.'nhachia  runtrata)  of  l>la(.-k(l(n\  n 
and  lialdon.     Upper  Greensand  (Meyei"'s  Bed  2)  of  Westou  Mouth  (Devon). 


Cypeina  cl.\xbiensis,  sp.  nov.     Plate  XXI,  fig.  2;    Plate  XXIV,  fig.  1. 

Descri[)llou. — Shell  large,  stout,  oval,  rather  elongate,  consideraljly  ineipiiluteral, 
moderately  convex.  Antero-dorsal  margin  short,  straight  or  slightly  concave. 
Anterior  margin  well  rounded,  passing  gradually  into  the  convex  ventral  mai-gin. 
Posterior  margin  oblique,  sul>truncate,  more  or  less  rounded.  Postero-doi'sal 
margin  rather  long,  slightly  convex.  Umbones  broad,  curved  anteriorly,  with  a 
rounded  carina  extending  to  the  postero-ventral  extremity,  and  limiting  a  flattened 
or  somewhat  convex  postero-dorsal  area  which  slo[)es  rapidl}'  to  the  postero- 
dorsal  margin,  but  more  gradually  to  the  posterior  margin.  Lunidar  region 
excavated,  not  limited.     Ornamentation  consists  of  small  concentric  ribs. 

Hinge :  in  the  right  valve  the  anterior  cardinal  is  conical,  larger  than  the 
median  cardinal,  and  placed  below  and  separated  from  the  latter;  tlie  posterior 
cardinal  is  oblique,  laminar,  and  divided  by  a  furrow.  In  the  left  valve  the 
anterior  and  median  cardinals  are  stout,  the  posterior  cardinal  is  obliijue  and 
laminar. 

Measurements  (ajjproximate)  : 

(1)  (2)  (■■<) 

Length  .  99         .         80         .         74  mm. 

Height  75         .         ()!•         .         5(i     „ 

Aljinilivs. — This  species  resembles  C.  Cuudanti,  Dollfus,'  from  the  Kimeridgian, 
1  Meulu  (le  Bracquegnies  ('  Mi-m.  cour.  et  Mt'm.  des.  Sav.  (.'traugers,'  vol.  x.\xiv,  1807).  i>.  Oy,  jil. 
viii,  figs.  2G— 28. 

-  '  Quart.  Jouru.  Geol.  Soc.,'  vol.  vi  (1850),  p.  182,  pi.  xxii,  figs.  1—3.  C.  globom,  Sharin;  (ILiJ., 
p.  182,  pi.  XV,  fig.  1)  is  recorded  by  Morris  from  Blackdowu,  but  I  have  seeu  uo  example  of  it. 

•■'  'Palffiont.  ludica,  Cret.  Fauua  S.  India,'  vol.  iii  (1870),  p.  189.  See  also  Meek.  'luvert.  Cret. 
aii.l  Tert.  Foss.  U.  Missouri'  (1876),  pp.  147—152. 

■i  '  Fauue  Kimmrrid.  du  Cap  de  la  Hcve '  (1863).  p.  65,  pi.  x,  figs.  6—8.     De  Loriol  and  Pellat. 
'  Mou.  Etages  supur.  Jiuuss.  de  Boulogue-sm--Mer  '  (187-1).  p.  42,  pi.  xii.  fig.  14. 


136  CRETACKUUS    LAMbJLLiUUAM'll  1  A. 

Ijut  is  much  lari^vr  ami  stouter,  and  the  luimlar  reg-ion  is  more  deeply  excavated; 
also  the  uinliniies  appear  to  have  a  greater  anterior  curvature. 

Type. — From  Benniworth  Haven,  in  the  Sedgwick  Museum. 

Bidrlhntiun. — Claxby  Ironstone  (zone  of  Bclemnitcs  lateralh)  of  Benniworth 
Haven  and  Donnington. 


CyI'EIXA  teali;ikxsi8,  sp.   no  v.     Plate  XX,  fig.  Von,  h. 

Dcscriptiuii. — Shell  very  thick,  large,  elongate,  oval,  regularly  convex,  very 
ine(|uilateral.  Antero-dorsal  margin  concave.  Anterior  margin  rounded,  curving 
rapidly,  passing  gradually  into  the  ventral  margin.  Posterior  margin  rounded, 
forming  an  obtuse  angle  with  the  long,  slightly  convex  postero-dorsal  margin. 
Umbones  broad,  anterior,  curved  inward.  A  faint  carina  extends  from  the  umbo 
to  the  po.sterior  end.  Luuular  region  deep.  Escutcheon  large,  deep,  limited  by  a 
strong  carina.     Ornamentation  consists  of  growth-ridges. 

Measurement^! : 

(1)  (-') 

Length  ....       105         ..         62  mm. 

Height  .         .         .         .         82         .         .         49     „ 

(1,  i)  Tealby  Limestoue. 

Affinifirs. — In  its  elongate  form,  and  deep,  carinate  escutcheon  this  species 
resembles  G.  huluniensi.s,  de  Loriol,i  from  the  Portlandian. 

Iiemarls. — There  are  two  specimens  in  the  Sedgwick  Museum  and  one  in  the 
British  Museum.     The  hinge  has  not  been  seen. 

Dldv'ibutiun. — Tealby  Limestone  of  Walesby  and  Claxby,  Lincolnshire. 


CvriiiXA,  sp.     Plate  XXT,  fig.  3. 

A  large  Gi/priiKi  from  the  Tealby  Limestone  of  Claxl)y  is  known  by  a  right 
and  a  left  valve,  now  in  the  Sedgwick  Museum,  and  appears  to  belong  to  a  distinct 
species.  It  shows  some  resemblance  to  G.  niKjnbttn,  Sowerby  (sec  page  141),  Ijut 
differs  from  that  species  in  the  greater  ventral  slope  of  the  postero-dorsal  mai-gin ; 
the  greater  obliquity  of  the  jiostcrior  margin ;  tie  smaller  ciirvature  of  the 
umbones  ;  the  longer  and  less  concave  antero-dorsal  margin  ;  and  in  the  absence 
of  a  carina  cutting  off  a  postero-dorsal  area.  The  surface  of  the  shell  is 
imperfectly  preserved,  but  in  places  there  is  evidence  of  well-marked  gi-owth- 
ridgcs.     Length,  92  nnn.     Height,  80  mm. 

'  De  Loiiol  aud  iVllat,  '  Porlliiudicu  du  Boulogue-sur-Myr  '  (18(JG),  p.  h-k  pi.  v,  fig.  9. 


CYPRINA.  l;'7 

CynuNA,  sp.     Plate  XX,  []g.  1  I-. 

A  few  spcciiiious  of  a  small  ( 'i/priuu,  with  the  .shell  iiii|)ei'lectly  [irescrved, 
liave  been  found  in  tlie  Sj)eetoii  Clay  (!_),  1). 

Cvi'KiXA  ANGLICA,  sp.  nov.     Plate  XX,  figs.  15,  l(i.     i'late  XXI,  fig.  la,  b. 

Description. — Shell  of  moderate  size,  oval,  inflated,  very  inequilateral.  Anterior 
margin  rounded,  forming  a  continuous  curve  with  the  convex  ventral  margin. 
Posterior  margin  less  convex  than  the  anterior,  sometimes  slightly  truncated,  more 
or  less  oblique,  usually  curving  gradually  to  join  the  ventral  margin.  Postero- 
dorsal  margin  long,  slightly  convex.  Antero-dorsal  margin  short,  nearly  straight. 
Uinbones  broad,  anterior,  curving  inward  and  forward.  I'ostero-dursal  part  of 
shell  slightly  compressed;  carina  al)sent  or  indistinct,  liiinuk' ovate,  dei)ressed, 
more  or  less  distinc-tly  limited.      (Jrnamentation  consists  of  growth-lines. 

Measurement  : 

(2)  (.-5)  (4.) 

41  .  38  .  32 
33  .  31  .  24 
26-5      .         24         .         lG-5      . 

(1  —  0)  Crackers,  Alhwfield. 

Affinilii'K. — ('.  iiu(jllr(i  does  not  appear  to  be  closely  related  to  any  other 
English  species.  Externally  it  shows  some  resemblance  to  G.  (uujnlatn,  8owerby 
(see  below),  l)ut  is  of  much  smaller  size,  more  elongate,  with  a  more  or  less 
distinctly  limited  lunule,  and  either  without  a  carina  or  with  an  indistinct  carina 
near  the  innbones. 

Iiemarls. — Nearly  all  the  specimens  show  the  two  valves  united,  so  that  the 
hinge  and  pallial  line  do  not  appear  to  have  been  seen  by  jirevious  workers ;  this 
probably  accounts  for  the  fact  that  in  several  collections  the  species  has  been 
referred  to  the  genus  Venus.  A  left  valve,  from  which  I  have  removed  the  matrix, 
shows  that  the  hinge  agrees  with  ('ii^iriint,  and  that  there  is  no  pallial  sinus. 

Type. —  In  the  Sedgwiek  Museum,  Cauibi'idge. 

Distribatiuu. — Lower  Ureensand  (Crackers)  of  Athcrfield.  Atherfield  Beds  of 
Peasemarsh. 


CvriJiNA    (Vkmlhaimha)    pkotkxsa,  sj).   nov.      IMate  XXI,    figs.    4 — 7.     Text-figs. 

2U,  21. 

1845.     Cyi'iuna    .\NauLATA,  E.  Fm-hes.     Quart.  Joiirii.  Gcol.  Soe.,  vul.  i,  y.  I'iO 

(^(iWi'm). 


(1) 

Length 

42 

Height 

35 

Thickness 

28 

(5) 

(6) 

27 

21    mm 

20 

M--3  „ 

14-5      . 

l»-5  „ 

138 


CJtETxiCl<:uL8    LAMELLlliKAAClllA. 


Descrqilion. — yiiell  large,  oval,  convex,  moderately  inequilateral,  anterior  pari 
produced.  Antero-dorsal  margin  concave.  Anterior  margin  rounded,  ])assing 
gradually  into  the  convex  ventral  margin  wliicli  curves  upward  to  join  the 
posterior  margin.  Posterior  margin  i-ounded,  sometimes  forming  a  large  and 
rounded  angle  with  the  ventral  margin,  but  sometimes  passing  into  it  gradually. 
Postero-dorsal  margin  convex.  Postero-dorsal  part  of  valves  compressed,  some- 
times limited  by  an  indistinct  carina.  Umbones  prominent,  curving  forward  and 
inward.  Lunule  indistinctly  limited.  Escutcheon  narrow,  deep,  with  a  sharp 
edge.     Ornamentation  consists  of  growth-lines. 


Fm.  20. — Cijprina  (Vcnilicardia)  proUnsa,  sp.  nov.     Lowi-r  (JivcnsanJ  (i'c)«u-)jud),  AtliorCukl. 
Socls""ick  Museum.     Kiirlit  valvt'.      x   -J. 


Measurements 
(1) 
lOG 

84 


Leni>th 

o 

Height 


(2)  (3)  (4) 

105         .       103         .         99 

89         .         91         .         88 

(1—6)  Perna-hcd.  Atlu'ilifkl. 
(0)  Crackers,  Atliorfiekl. 


(5) 

("!) 

75 

■ID  mm 

60 

■10     „ 

AJfinUics. —  The  characters  which  distinguisli  this  species  fVom  (_'.  (uujuhdii, 
Sowerby,  are :  the  umbones  are  less  anterior  and  the  shell  is  less  inequilateral  ; 
the  umbonal  part  of  the  shell  is  relatively  smaller;  the  carina  is  less  distinct;  the 
anterior  part  of  the  shell  is  more  produced ;  the  posterior  part  is  more  I'oundcd  ; 
the  ventral  margin  has  a  greater  cui'vature;  the  shell  is  less  inflated,  so  that  the 
marginal  parts  of  the  valves  meet  at  a  smaller  angle.  The  anterior  i)art  of  the 
shell  resembles  that  of  C.  tnuicafa,  but    tlie  posterior  part  is  more  rounded,  and 


CYPRINA. 


139 


the  postero-dorsal  margin  has  a  greater  ventral  slope.     G.  ijrotensa  belongs  to  the 
sub-genus  Vcnilicardin,  Stoliczka.' 

Type. — In  the  Sedgwick  Museum ;  from  the  Pernn-bed  of  Atherfield. 

Distribution.— Lower   Greensand  :   rerna -bed    of    Atherfield    and    Sandown. 


Fia.  21. — C'ljprinn  (Vtnilicardia)  protensa,  sp.  nov.     Lower  Greensand  {Pema-hci),  Atherfield. 
Sedgwick  Museum.     Eight  valve,      x  -J. 

Crackers   of   Atherfield.      Ferruginous    Sands   of    Slmnklin    (Meyer   Collection). 
Atherfield  Beds  of  Peasemarsh. 


Cvruix.v  SowEunvr,  d'Orhign)/,  1850.     Plate  XXI,  figs.  S,  0.     Text-fig.  22. 


183G.     Cyprina  ANG1JI.ATA,  .7.  iJi;  C.  Soirerhy.     Trans.  Geol.  Soc.,  ser.  2,  vol.  iv, 

p.  128. 
1845.  —  E.  Forbes.     Quart.  .Toiiru.  Geol.  Soc,  vol.   i.  p.  24<) 

(parliin). 
1850.  —         SowERBYi,  A.  (VOrhigny.     Proilr.  iIp  Pal.,  vol.  ii,  p.  78. 

18.54.  —         ANouLATA.  J.  MnrrSf.     Cat.  T.rit.  Fos.s.,  e<l.  2,  p.  IHO  {/lartim). 


Mensur  erne  lit. •: 


.s  : 


Length 
Height 


(1)  (2) 

71         .         Gl 
GO         .         51         . 
(1,  2,  4)  Hvthc  Beds.  nvUic. 

(3)  Lower  Greeusaml,  near  Atherfield 


(3) 
50 

52 


(4) 

55  mm. 

■I'S     „ 


Palteont.  ludica,  Cret.  Fauna  S.  India.'  vol.  iii  (1870),  p.  IW. 


140 


CRETACEOrS    LxV:\rEIJJBR ANCHTA. 


liiniKirls. — Internal  casts  of  Cijjirutu  are  found  commonly  in  the  Hytbe  Beds 
of  Hythe,  etc.  Those  from  the  "  rag  "  have  their  original  form  well  preserved,  but 
the  specimens  found  in  the  softer  greensand  beds  are  more  or  less  crushed.  One 
example  of  tlie  same  species  with  the  shell  preserved  has  been  obtained  from  the 
Eower  Greensand  between  Atherfield   and    BlnekgaTig.      The   form  of  t1ie  shell 


'';f*<^ 


Fio.  22.— Cypiinrt  Smeerhyi,  d'Oib.     Lower  Greensand,  Parliam  Park.     Britisli  Museum,  No.  5933. 
Internal  cast.     Left  valve,  and  dorsal  view  of  both  valves,      x  ^. 

resembles  that  of  C.  Uiwolatd  (see  below),  but  the  anterior  curvature  of  the 
unibones  is  considerably  less,  and  the  postero-dorsal  margin  of  the  shell  is  less 
convex.  It  is  difiicult  to  determine  satisfactorily  the  affinities  of  this  species  until 
more  specimens  with  the  shell  have  been  ol)tained.  It  may  l)e  identical  with  the 
form  from  tlie  Up])er  Ajitian   of  8te.  Croix  and   tlie    I'ei'te-du-RhAne  referred  l)y 


CYPRINA.  Ill 

Pictet  and  Roiix  '  to  ^ '.  '  yn/r;/.s/.s,  LcyiiiL'rie,  ami  Ijy  Pictet  and  Cainpiclie  -  to  (J. 
anijulafa,  Sowerby.  English  examples  were  identified  with  G.  arifjiilala  by  J.  de  C. 
Sowcrby,  Forbes,  and  Morris,  but  were  regarded  by  d'Orbigny  as  belonging  to  a 
distinct  species  which  he  named  G.  Sowerhiji,  and  mentioned  as  types  the 
specimens  collected  by  Fitton  from  the  Hythe  Beds  near  Folkestone.  G.  Soiverbyi 
also  resembles  G.  neocomiensu,  d'Orbigny.^ 

Bhtribution.—Hyihe  Beds  of  Hythe.    Sandgate  Beds  of  Pailiam  Pai-k.    Lower 
Greensand  between  Atherfield  and  Blackganff. 


^^"'"O' 


Cyfkixa   (Venilicardia)   ANCiULATA  {Sowcrhij),  181k     Plate  XXII,  figs.  1— i. 

Text-figs.  23,  24. 

1814.     Venus  angulata,  /.  Sowerhy.     Min.  Conch.,  vol.  i,  p.  14-5,  pi.  Ixv. 

1828.     Cyprina  angulata,  J.  Flcmimj.     Hist.  Brit.  Animals,  p.  4-14. 

1836.  —  —         J.  de  C.  Sowerhi/.     Trans.  Gcol.   Soc,  ser.  2,  vol.   iv, 

p.  240. 
1850.  —  —A.  d'Orbiyiuj.     Proclr.  de  Pal.,  vol.  ii,  p.  161. 

1854.  —  _         /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  199  (farlim). 

1870.  —  —         i^.  Stoliczka.     Palaeout.  Indica,  Cret.   Fauna  S.  India, 

vol.  iii,  p.  19.3. 

Non  1868.  —  -  A.  Briart  and  F.  L.  Cornet.     Meule  de  Bracqiicgnies 

(Mem.  cour.  et  Mem.  dcs  Sav.  t'trangers, 
vol.  xxxiv),  p.  68,  pi.  viii,  figs.  26—28. 

Description. — Shell  large,  sub-quadrate,  rounded,  very  inequilateral,  moderately 
inflated.  Anterior  margin  rounded,  passing  quickly  into  the  ventral  margin, 
with  which  it  forms  a  regular  and  continuous  curve.  Posterior  mai'gin  more  or 
less  truncated,  slightly  or  moderately  convex,  usually  olilique,  and  forming  an 
obtuse  angle  with  the  postero-dorsal  margin.  Uml)ones  large,  broad,  anterior. 
A  more  or  less  distinct  carina  passes  from  the  umbo  to  the  ])ostero-ventral 
angle,  cutting  off  a  postero-dorsal  area,  which  slopes  rather  rapidly  to  the  posterior 
margin.  Lunular  region  more  or  less  depressed,  not  limited.  Escutcheon  narrow, 
deep,  limited  by  a  sharp  carina. 

Ornamentation  consists  of  growth-lines. 

In  the  right  valve  the  posterior  cai'dinal  tooth  is  large  and  divided ;  the 
median  cardinal  is  smaller  than  the  anterior  cardinal,  and  in  most  forms  adjoins 

1  Pictet  and  Eoux,  '  Moll.  Foss.  Grcs  verts  de  Geuuve '  (1852),  p.  444,  pi.  xxxiv,  fig.  1. 

2  'Terr.  Cret.  de  Ste.  Croix  '  (1865),  p.  221. 

3  '  Pal.  Franc.  Ten-.  Cret.,'  vol.  iii  (1847),  pp.  98,  759,  pi.  cclxxi.  Afterwards  referred  U<  C. 
bemensis,  Lejmerie,  see  d'Orbignv,  '  Prodr.  de  Pal.,'  vol.  ii  (1850),  p.  77. 

19 


1-1-2 


CRETACEOUS    L.OrELLTBRAXCTTTA. 


the  postcro-dorsal  side  of  the  hitter,  but  in  examples  in   which  the  umbones  are 
more  anterior  in  position  the  median  cardinal  is  dorsal  to  the  anterior  cardinal, 
and  is  almost  continuous  dorsally  with  the  posterior  cardinal  tooth. 
Measurements  : 

(3)  (4) 

.     911     .     98     . 
86     .     8G     . 
(1—8)  BlackdowD. 

Affinities. — Specimens  of  Gijprlna  from  the  Aptian  and  Gault  of  the  Perte  du 
Rhone  and  Ste.  Croix  were  referred  by  Pictet,  Roux,  and  Renevicr,  to  G.  ervyensis, 
Leymerie,  but  were  subsequently  identified  with  C.  auijitJitln  hy  Pictet,  Renevier, 


(1) 

(2) 

Length  . 

103 

.  lO-i 

Height  . 

92 

.     90 

(5) 

(6) 

(7) 

(8) 

9G 

89 

87 

82  mm 

86 

79 

79 

70     „ 

\ 


Fig.  23. — Cyprina  (Venilicardia)  angxdata  (Sow.).     Upper  Greeiisaud,  lilackilown.     MusuuiiX  uf  I'ractical 
Geology,  No.  18698.     Right  valve,  and  anterior  view  of  both  valves,     x  *. 

and  Campichc.^  Pictet  and  Campiche,  after  an  examination  of  specimens  from  the 
Gault  of  Nievre  and  Yonne,  came  to  the  conclusion  that  G.  ervyensis,  as  described 
and  figured  by  Leymerie-  and  d'Orbigny,^  must  be  regarded  as  a  synonym  of 
G.  angulata.  I  have  had  no  opportunity  of  comi)aring  French  specimens  with 
examples  from  Blackdown,  but  so  far  as  I  can  judge  from  the  figures  of  G.  eroyensis 
tliere  appear  to  be  some  differences,  consequently  I  do  not  at  present  feel  justified 
in  including  G.  crryensin  as  a  synonym  of  G.  anguhdd. 

1  Pictet  and  Rous,  'Moll.  Foss.  Givs  verts  de  Geneve'  (1852),  p.  444,  pi.  xxxiv,  fig.  1.  Pictot  and 
Keuevier,  '  Foss.  Terr.  Aptieu  '  ('  Matt'r.  Pal.  Suisse,'  ser.  1, 185(3-58),  pp.  75, 177.  Pictet  and  CampicLe, 
'Terr.  Crct.  Ste.  Croix'  ('Mater.  Pal.  Suisse,'  ser.  4,  1805),  p.  221. 

-  '  Mem.  Soc.  gt'ol.  de  France,'  vol.  v  (1842),  pp.  5,  25,  pi.  iv,  figs.  6,  7. 

3  '  Pal.  Fraue.  Terr.  Cret.,'  vol.  iii  (1844),  p.  102,  pi.  cclxxiv. 


CYPRINA.  j.i3 

G.  angtdafa  of  Briart  and  Cornet  appears  to  be  closely  related  to  C.  aineaia, 
Sowerby  (see  p.  134). 

0.  {Venilicardia)  Jid-eni,  dc  Loriol,'  from  the  Gault  of  Cosne,  resembles  some 
forms  of  G.  angulata.- 

Beviarl-s. — G.  aiK/ulafa  varies  in  its  relative  height  and  length,  and  in  I  lie 
position  of  the  umbones.  The  shell  is  usually  stont,  Init  occasionally  rathcf  lliin. 
Sowerby  gives  a  good  figure  of  G.  angnlata,  except  (liat  the  teeth,  as  pointed  out 
by  Rtoliczka,  are  not  correctly  drawn." 


Fig.  2t. — Cyprina  (Venilicardia)  angulaia  (Sow.).    Upper  Greensand,  Blackdown.     Sedgwick  Museum. 
Eight  valve  x  ^.     Tlie  hinge  of  this  specimen  is  shown  on  Plate  XXII,  fig.  2. 

Types. — From  the  Upper  Greensand  of  Blackdown,  in  the  British  IMuseum. 

Distribution. — UjDiJer  Greensand  (zone  of  Sclda'iibachia  rostrnta)  of  Blackdown 
and  ITaldon.  Recorded  by  Jukes-Browne  from  the  TiOwor  Gault  of  A\'iltshiro,  and 
from  the  Upper  Greensand  of  the  Isle  of  Wight. 


CvrKiXA    (VENnjr.\TjmA)    ltnkoi.ata    {Soirn-lii/),    18]  3.      ?lat(>    XXII,    figs.   5 — 8. 

Plate  XXIII,  figs.  1,2. 

1811.     Venus  castrensis,  J.  Parkinariii.     Organic  Eemaius,  vol.  iii,  p.  1H7  (uou 

V.  cagtrensis,  L.). 


1  '  Gavdt  de  Cosne '  (1882),  p.  68,  pi.  ix,  fig.  1. 

-  Morris  records  Cyprina  globosa,  Sharpc,  from  the  Gi-eonsand  of  Bliuk.lowu,  l.ut  I  Iiiivc  not  seen 
any  specimen  from  that  locality.  Morris,  '  Cat.  Brit.  Foss.,' ed.  2  (18.54).  p.  100.  Sbarpo,  'Quart. 
Jouni.  Geol.  Sop.,'  vol.  vi  (18-50),  p.  182.  pi.  xv,  fis,'.  1. 

^  From  tlu>  remark  on  Sowerby's  figiire  made  1>\-  Biiart  and  Cornet  (p.  l!f>)  I  can  only  conclude 
that  thi'v  Iiail  not  seen  sjiecimens  of  C.  angulaUt. 


144  CRETACEOUS    LAMELLTBRANCHIA. 

1813.     Venus  likeolata,  /.  Sowerby.     Miu.  Couch.,   vol.  i,  p.  ^>7,  pi.  xx  (upper 

figure). 
1828.         —  —  /.  Fleming.     Hist.  Brit.  Auimals,  p.  449. 

1836.     Cypeina  rostrata,  J.  de  C.  Soiverbij.     Trans.  Geol.  Soc,  ser.  2,  vol.  iv.  pp. 

240,  341,  pi.  xvii,  fig.  1. 
183C.     Cytherea  lineolata,  Snverhy.     Iliid.,  p.  240. 
1850.     Cyprina  rostrata,  A.  cVOrhicjmj.     Prodr.  do  Pal.,  vol.  ii,  p.  161. 
1864.  —  —         J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  199. 

1854.     Cytherea  lineolata,  Mnrris.     Il)id.,  p.  200. 

18C5.     Cyprina  rostrata,  F.  J.  Picfet  aud  G.  Cainpichc.    Foss.  Terr.  Cn't.  Stc.  Croix 

(Mater.  Pal.  Suisse,  ser. 
4),  pp.  222,  229. 
1870.  —  —  F.  StoUczha.     Paloeont.  Indica,  Cret.  Fauna  S.   India, 

vol.  iii,  p.  193  (VenlUcarilla). 
1907.  —        lineolata,  R.  B.  Newton.     Proc.  Malacol.  Soc.,  vol.  vii,  p.  284, 

pi.  xxiv,  fig.  14. 

Non  1844.  —  —A.  (VOrligny.     Pal.  Franc.  Terr.  Cn't,,  vol.  iii,  p.  98, 

pi.     fclxxi     (Cyprina    neocomiensin. 


d'Orbigny,  Ibid.,  p.  759). 


Measurements  .- 


(1) 

(-') 

(3) 

(4) 

Length 

71 

()7 

66 

52  mm 

Height 

Gl 

GO 
(1—4)  Blackdown. 

58 

.         43    „ 

Affinities. — This  species  differs  from  G.  nnfjnlata  in  its  more  prominent  and 
more  strongly  curved  umbones,  in  tlie  shorter  posterior  margin  and  tlie  greater 
slope  of  the  postero-dorsal  margin,  and  in  the  more  deeply  depressed  luniilar 
region.  IMic  hinge  also  differs :  in  the  right  valve  the  median  cardinal  tooth  is 
tlistinctly  separated  from  the  anterior  cardinal  and  is  dorsal  to  the  latter  and 
continuous  with  the  posterior  cardinal  tooth  ;  the  latter  is  either  undivided  or  the 
division  is  indistinctly  shown. 

Bemarlcs. — C.  linedlatu  varies  considerably  in  the  prominence  and  curvature  of 
the  umbones,  and,  as  a  result,  in  the  outline  of  the  shell.  An  extreme  form  was 
figured  by  J.  de  C.  Sowerby  as  the  type  of  ('.  rostrata;  in  specimens  in  which  the 
umbones  are  less  ))rominent  and  their  anterior  curvature  less  pronounced  the  out- 
line of  the  shell  becomes  less  triangulai-,  and  in  some  cases  approaches  that  of  G. 
nngvlata,  but  the  differences  in  the  liinge  of  the  right  valve  and  the  greater  depth 
of  tlu'  hiuular  ivgioii  appear  to  l)e  present  in  all  specimens.  The  average  size  of 
this  species  is  considerably  less  than  that  of  ('.  (iiujiddta. 

The  type  of  ^^;//^•^■  liiiniltilit,  Sowerby  (!'.  castrensis,  Parkinson),  from  IJlack- 
down,  agrees   willi    tlic   iioi'uial   forms  of   G.   riixlr(it<i,  except  for  tlie  presence  of 


CYPRINA.  145 

numerous  W-sliaped  markint>-s  on  the  surface.  Tliese  appear  to  l)e  clue  to  the 
structure  of  tlie  shell  (possibly  connected  with  colour  markings),  since  they  are 
seen  only  in  specimens  which  are  somewhat  decorticated,  and  are  in  some  cases 
present  on  one  valve  but  not  on  the  other,  or  are  seen  on  the  dorsal  but  not  on 
the  ventral  part  of  a  valve. 

Stoliczka'  thought  that  Venns  Hnnolnta  was  probably  identical  with  Cijthpren. 
jilana,  Sowerby,  but  the  hinge  and  pallial  line  of  the  former  prove  conclusively 
that  it  belongs  to  the  genus  Gi/priua. 

Types. — From  Blackdown ;  Venus  Uneolata  in  the  British  Museum  ;  (,'.  rosfrtiln 
in  the  Bristol  Museum. 

Distrihnfloii. — Upper  Greensand  (zone  of  Schloenbochia  rostrata)  of  Blackdown. 


CvrruxA  (Vi-^nilicardia)  tkuncata  (Suwry/ji/),  1836.     Plate  XXIII,  fig.  3. 

183G.     Venus  ?  truncata,  /.  dr  C.  Sowcrhy.     Trans.  Geol.  Soc,  scr.  2,  vol.  iv, 

pp.  242,  341,  pi.  xvii.  fig.  3. 
1850.         —  suBTRUNCATA,  A.  irOrbiijiitj.     Prodr.  de  Pal.,  vol.  ii,  p.  159. 

18.54.     CvTnEREA  TRUNCATA,  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  201. 
1865.     Venus  subtruncata,  F.  J.  Piciet  and  G.  Campiche.     Foss.  Terr.  Cret.  Stc. 

Croix  (Mater.  Pal.  Suisse,  ser.  4),  p.  190. 
1870  —  —  ii".  Stoliczka.     Pateont.  Indica,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  161  (Caryatis). 

Affinities. ^=^—0.  truncata  is  closely  allied  to,  and  probably  only  a  variety  of 
C.  angidafa.  The  shell  is  thinner,  the  posterior  margin  higher,  and  the  anterior 
part  more  produced  than  in  C.  anguluta. 

This  species,  or  variety,  has  hitherto  been  referred  to  Yenva  or  Cijtiieren,  but 
a  specimen  showing  the  hinge  and  pallial  line  proves  that  it  is  a  Ci/priiia.  The 
hinge  agrees  with  that  of  (J.  angulatn. 

An  example  collected  by  the  late  Rev.  W.  Downes  (Plate  XXTII,  fig.  4)  is 
more  elongated  and  more  inflated  than  the  type  of  G.  truncata,  but  agrees  in  other 
respects,  and  is  probai)ly  only  an  individual  variation. 

jTy/jJC. — From  Blackdown  ;  in  the  Bristol  Mu.seum. 

Distribution. — Upper  Greensand  (zone  of  Schla'tibachia  rostrata)  of  Blackdown. 


CvnaxA   i,I(;ei!IKXSis,  crOrbignij,  1844. 

Tntornal    casts    of    a    large    Ci/prina    have    been    found   in    the    C'enomanian 
Siiiidstdnc  (if   Wilmington,-  Devon,  and  in  the  cherty  blocks  in  the  Eocene  Cnivel 

'   •  Cret.  Fauna  S.  India,'  vol.  iii  (1870),  i)p.  1(J0,  1G9. 

-  Jukes-Browne,  'Cret.  Bocks  of  Britain,'  vol.  ii  (1903).  p.  129. 


14G  CRETACEOUS    L  AIMELLIBRANCHIA. 

(derived  from  tlic  Upper  Greensand)  of  Aller  Vale  near  Torquay.  They  have 
been  identified  with  C.  ligeriensis,  d'Orbigny/  by  Mr.  Jukes-Browne,  wlio  has 
compared  them  with  examples  of  that  species  from  the  Cenomanian  of  Vimoutiers 
and  Orliiquet,  and  states  that  the  agreement  is  very  close.  The  English  specimens 
also  resemble  C.  Noudiana,  d'Orbigny,"  of  which  a  cast  only  is  figured  b}^ 
d'Orbigny,  and  was  at  first  regarded  as  C.  lifjcriemis^.  An  example  from 
Wilmington  is  in  the  Sedgwick  Museum.  Otiiers  from  Aller  Vale  are  in  the 
'i\ir(|uay  Museum  and  in  the  Sedgwick  Museum. 


Cyi'Imna  (Ykxif.k  Ai;niA  ?)  quadeata,  iVOrhvjinj,  ISll.     Plate  XXIII,  figs.  G — 9. 

1840.     TsocAEDiA  CEETACEA,  TI.  B.  Gcuiifz.     Char.  (1.  Schiclit.  u.  Pdrcf.  dcs  siichs. 

Kreidegeb.,   pt.    2,   ]>.    53,    pi.    xi, 
figs.  6,  7  (mow  Goldfuss). 
1844.     Cyprina  qitadeata,  A.  iVOrhi(puj.     Pal.  Fran?.  Terr.  Crct.,  vol.  iii,  p.  104, 

pi.  celxxvi. 
1850.  —  —  —  Trodr.  de  Pal.,  vol.  ii,  p.  161. 

—  —  —      '    H.  B.  Geinitz.     Das  Quadorsaiidst.  odcr  Kroidogeb.  in 

Deutseblaud,  p.  156. 
18(35.  —  —         F.  J.  Pictef  ami  G.  Campiche.     Foss.  Torr.  Cn't.  Sto. 

Croix   (Mater.    Pal.    Suisse,    ser.  4), 
p.  225,  pi.  cxv,  figs.  3 — 5. 
1870.  —  —        J^.  Stoliczka.     Paloeout.  ludiea,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  193. 
1873.  —  —         R.  B.  Geinitz.     Das  Elbtbalgeb.  in   Sachsen  (Palfconto- 

grapbica,  vol.  xx,  pt.  2),  p.  62,  pi.  xvii, 
figs.  14 — 16. 
'^  1877.  —  —         A.  Frit.'irh.     Stud,  im  G-ebiete  der  buliiii.  Krcidcfonnat. 

II    Weissenberg.    u.    Maluitz.    Schiclit., 
p.  116,  fig.  70. 
?  1883.  —  —  —  Ibid.,  Ill  Iscrsobieht.,  p.  100,  fig.  65. 

1895.  —  —         E.     Tiessen.      Zeitsclir.    d.    deutscb.    gcol.    Gescllscb., 

vol.  xlvii,  p.  486. 
1807.     Aectica  —         n.  Woods.     Quart.  Joiirn.  Geol.  Soc,  vol.  liii,  p.  390, 

pi.  xxvii,  fig.  25,  pi.  xxviii,  fig.  1. 

Dem-ij^tiov. — Shell  sul)-rhomboidal,  much  inflated,  rather  strongly  carinate, 
very  inequilateral ;  length  somewhat  greater  than  height.  Anterior  margin 
rounded,  passing  gradually   into  the  slightly  curved  ventral    margin.     Posterior 

1  'Pal.  Franc.  Terr.  Crct.,'  vol.  iii  (1844),  p.  103,  pi.  eclxxv,  figs.  1,  2;  '  Prodr.  de  Pal..'  v..l.  ii 
(1850),  p.  161  ;  Gucrangcr,  'Album  Paleont.  de  la  Sarthe,'  1867,  p.  13.  i>l.  xvii,  figs.  1,  5. 
-  Op.  r!l.  (1844).  pi.  eclxxv,  figs.  3,  4;  op.  cit.  (1850),  p.  195. 


CYPRINA. 


117 


margin  truncated, 


hi"'li. 


Postcro-dorsal  region  flattened.     Umbones  pi-oniinent, 


anterior,  curved  inwards, 
concentric  striae. 
Measurements  : 


Lunnlar  region  excavated. 


Ornamentation  consists  of 


(1) 

(-') 

(3)           (1)           (5)           (0)            (7) 

Length  . 

54 

40 

37       35       26       23       4(3 

Height   . 

40 

41 

34       31       24       19       39 

(1—6)  Gault,  Folkestone. 

(7— !;i)  Rye  Hill  Sand,  Warmiuster. 

(10)  Cbloritic  Marl,  MaiJeu  Bradley 

(11)  Base  of  Chalk,  Chard. 

(«) 

10 


(9) 

20 
15 


(10) 

45 

38 


(11) 

58  mm. 
52    „ 


Affinities. — In  G.  ligeriensit^,  d'Orbiguy,^  the  umbones  are  less  auterioi-  in  [nm- 
tion,  and  the  angle  between  the  posterior  and  the  dorsal  margins  is  larger  than  in 
G.  (jnadrata. 

G.  retjularis,  d'Orbigny,-  is  distinguished  from  C.  qudtlralti  by  its  k>ss  ine(jui- 
lateral  and  more  regularly  globose  shell,  by  its  less  incurved  umbones,  and  the 
smaller  truncation  of  the  posterior  end. 

G.  crassLcornis  (Agassiz)'^  possesses  a  relatively  higlier  and  less  inequihiteral 
sliell,  witk  moi'e  prominent  umbones,  which  are  not  so  nuicli  curved  anterioi'Iy 
as  in  G.  quadrata. 

Ri'marlis. — The  specimens  from  the  Gault  liave  the  shell  more  or  less  i)erfect]y 
preserved,  but  most  of  the  examples  from  higher  beds  are,  like  the  type,  in  the 
form  of  internal  casts.  The  specimens  found  in  the  Chalk  Rock  are  rather 
imperfect,  but  do  not  appear  to  differ  specifically  from  those  found  at  lower 
horizons. 

Type. — The  locality  of  the  type  is  not  given  by  d'Orbigny,  but  he  records 
specimens  from  the  Ceuomaniau  of  Villers  (Calvados),  Rouen,  St.  Calais  (Sarthe), 
etc. 

Distribution. — Upper  Gault  of  Folkestone.  Upper  Greensand  (zone  of  Scldwn- 
hachia  rostrata)  of  Devizes  {fide  Jukes-Browne).  Rye  Hill  Sand  of  Warminster. 
Base  of  the  Chalk  of  Chard.  Cldoritic  Marl  of  Maiden  Bradley  and  the  Isle  of 
Wight.     Chalk  Rock  of  Morgan's  Hill  near  Devizes,  Cuckhamsley,  and  Luton. 

1  '  Pal.  Fran?.  Terr,  Cret.,'  vol.  iii  (18-14),  p.  103,  pi.  ccl.\xv,  fi},'s.  1,  2  (not  3,  4). 

-  Ibid.,  p.  100,  pi.  cel.x.xii,  figs.  3—0  ;  Tictet  and  Campiche,  '  Foss.  Terr.  Cret.  Sle.  Croi.x  '  (1805), 
p.  "224,  pi.  cxv,  figs.  1,  2. 

3  '  Etudes  crit.  Moll.  Foss.,  Myes'  (1842),  p.  30,  pi.  viii/,  figs.  5—10  ;  Pictet  and  CauipicLe,  *  Terr. 
Crct.  Ste.  Croi.\'  (' Matrr.  Pal.  Suisse,'  scr.  4,  180.5),  p.  220,  pi.  cxv,  figs.  0—8. 


148  CRETACEOUS    LAMELLIBRANCHIA. 

Genvft — TifAPEZirM,  Mcgcrlc  v.  Muldj'i-ldt,  1811. 
('  Naturf.  Frcuude  zu  Berlin  Mag.,'  vol.  v,  p.  68.) 

Trapezium  ?  akcadifoeme  {Keeping),  1883.     Plate  XXIII,  figs.  10,  11. 

1883.     Cypeicaedia  aecadifoemis,  W.  Keepimj.     Foss.  etc.,  Neoc.   Upware  and 

Bru'lihill,  p.  120,  pi.  vi,  (ig.  (3. 

DcHcrqdiuii.. — Shell  trapezoidal,  iuHated ;  length  much  greater  than  height. 
Dorsal  and  ventral  margins  nearly  straight  and  nearly  parallel.  Posterior  margin 
oblique,  straight  or  slightly  curved,  forming  an  obtuse  angle  with  the  dorsal 
margin  and  an  acute  but  rounded  angle  with  the  ventral  margin.  Anterior  margin 
rounded.  Umbones  near  the  anterior  end,  much  curved,  with  a  strong,  rounded 
keel  extending  to  the  postero-ventral  angle.  The  part  in  front  of  the  keel  is 
slightly  concave,  giving  a  faint  sinuosity  to  the  ventral  margin  of  the  valve.  The 
triangular  part  dorsal  to  the  keel  is  compressed  and  flattened,  and  slopes  steeply  to 
the  margin.     Lunule  cordate.     Hinge  not  seen. 

Ornamentation  consists  of  small,  rounded  radial  ribs,  and,  at  intervals,  strong 
concentric  laminar  ridges ;  both  ribs  and  ridges  are  indistinct  on  the  part  dorsal  to 
the  keel.     Length  21  mm. ;  height  12*5  mm. ;  thickness,  13  nun. 

Ajfiiiitics. — This  species  is  more  elongate,  and  the  carina  is  more  angular  than 
in  T.  squamosum  (see  below). 

llonarks. — The  only  examples  seen  are  the  type  and  u  specimen  in  Mr.  J.  F. 
Walker's  collection. 

Ti/pe. — The  type  is  in  the  Sedgwick  Museum. 

Distribution. — Lower  Greeusand,  Upware. 


Tk.u'kziilm  ?  stiU.VMOSUM  {Ki'i'piiiij),  1883.     I'latc  XXlll,  iigs.  12—15. 

1883.     CypEiCARDiA  squajiosa,  W.  KfCjiiiKj.    Fona.,  etc.,  Neoc.  Upware  and  Brick- 

liill.  p.  120,  pi.  vi,  fig.  5. 

Descriiilldu. — Shell  rounded-oblong,  much  inflated,  highest  near  the  posterior 
end.  Dorsal  margin  nearly  sti'aight;  the  posterior  forms  a  regular  curve,  which 
passes  into  the  slightly  concave  ventral  margin.  Dorsal  part  of  anterior  margin 
concave,  ventral  part  rounded.  Umbones  prominent,  anterior,  much  curved.  A 
broad,  rounded  ridge  extends  from  the  umbo  to  the  postero-ventral  extremity  and 
divides  the  shell  into  two  parts.  The  part  in  front  of  the  ridge  is  slightly  concave, 
the  part  above  is  larger  and  convex.     Lunule  cordate. 

Ornamentation   consists  of  small   radial   rihs,  and,  at  rather  distant   intervals, 


(3) 

W 

13-5      . 

12-0    111  Ml 

11 

10       „ 

10-5      . 

9       „ 

TRAPEZIUM.  149 

strong  concentric  liiniell*.      Tlic  oriKunontation  is  indisliiicl  on  llic  ]iai't  alxjvc  the 
rounded  ridge.     Margin  of  valve  crenulate. 

MeasiU'i'iHcnts  : 

(1)  (2) 

Length         .         15-5      .         14 
Height  .  12  II 

Thickness     .  10         .  1() 

(1 — 4)  Lower  GreeusanJ,  Upwaro. 

.[(ji II 'dies. — Keeping  coniparetl  this  species  with  (JanlUn  iiajcoiiiirusis,  d"Oi-l)igiiy, 
to  which  it  shows  some  resemblance  in  general  form.  Bnt  the  faint  radial  ribs 
and  strong  concentric  lamella',  as  Avell  as  tlie  cliaraeter  of  the  hinge,  so  far  as  it 
can  be  made  out,  seem  to  connect  this  species  with  Tntjicxiniii,  ratlier  tlian  witli 
Gardita. 

Tijpe. — In  the  Sedgwick  Museum. 

Distr'ibutiuii. — Lower  Greensand,  Upwai-e. 


Trai'KZIUM  ?  sp.      riate  XXIII,  fig.  IG. 

1883.     Cypkicakdia  striata,  W.  KcepiiKj.   Fuss.,  utc,  Nuoc.  Upware  aud  Urickliill. 

p.  119. 

An  imperfect  left  valve  from  the  Lower  (Jreensand  of  Upware,  in  the  Sedgwick 
Museum,  was  identified  by  W.  Keeping  with  Gi/pricardin  driula  (Geinitz)  '  from 
the  Ceiioniauian  of  Saxony.  The  ribs  are  fewer  in  nuiubei-  than  in  the  examples 
of  C.  striata  figured  by  Geinitz. 


Ti;Ari:zirM  TUArE/.oin.vLi':  {lu'iinrr),  1811.     Tlate  XXIII,  figs.  17— H». 

18-41.     Crassatella  TitAriizoiDALis,  F.  A.  Itiiiiur.     Die  Versteiu.  d.  uorJ-deiitsL-h. 

Kreidcyelj.,   p.    74.    pi.    i.\, 

?  1847.  —  —  -1-   d'Aicluuc.     Mi'm.   Soc.   i,'L'ol.  du   Franco, 

sur.  2,  vi)l.  ii.  p.  302. 
1850.     Cyi'KINA  —  if     B.     Geinitz.      Das    Quadursaudst.    odor 

Kn-idogcb.  iu  Dcutsoli- 
laud,  p.  168  (/ic(Wim). 
1854.     C'ypRiCAKDiA  -  A.  d'Ovbiginj.     Prodr.  de  Pal.,  vol.  ii.  p.  240. 


1  •  Char.  d.  Schicht.  u.  Potrof.  des  siichs.  Kreide-eb.,'  pt.  2  (1840).  p.  52,  pi.  x,  fife'.  3.  Modiol,, 
cardiloiih->>,  (ieiuitz,  'Das  ElWliali^'elx  iu  Sa*;l)seu  '  (•  Palajoutoyrai.hica,'  vol.  xx,  pt.  1.  1873),  p.  218. 
pi.  xlviii.  fij,'s.  11—13  ;  pi.  .\iix,  tigs.  11»,  20. 


150  CRETACEOUS    LAMELIJlUIAXriTIA. 

1873.     Cyi'kina   tkapezuidalis,    H.    B.    Geinitz.     Das    Elbtbalgeb.    iu   Saelisen 

(PalBeoutographica,  vol.  xx, 
pt.  1),  p.  2211,  pi.  1,  fig.  6 
(?5). 

1889.     Cyi-kicakdia        —  E.    HuhapJ'd.     Die    Mollusk.    Aacheu.    Kreide 

(Palseontograpliica,  vol. 
xxxv),  p.  179. 

1897.     Teapezium  teapezoidale,  II.  Wumh.     Quart.  Jouni.  Geol.  See,  vol.  liii,  p. 

391,  pi.  xxviii,  figs.  9,  10. 

1901.  Cypeicaedia   teapezoidalis,   F.    Shinii.     Jalirb.   d.    k.   pi-eussiscli.   geol. 

Laudt'saust.  fiir  1900,  vol.  xxi, 
p.  80,  pi.  vii,  fig.  5. 

1902.  —  —  A.WollemcDui.    Liiueburg.  Kreide  (Abhaiidl. 

d.  k.  preussisch.  geol. 
Laudesanst.  N.  F.,  Heft. 
37),  p.  78,  pi.  ii,  fig.  3; 
pi.  iii,  fig.  1. 

Descriplhni. —  Sliell  trapezoidal,  rounded,  inflated.  Ventral  margin  sliglitly 
curved,  roughly  parallel  to  the  dorsal  margin,  and  passing  gradually  into  the 
rounded  anterior  margin.  Posterior  margin  oblique,  forming  an  obtuse  angle  with 
the  dorsal  margin  and  an  acute  angle  with  the  ventral  margin.  Umbones  near  the 
anterior  end,  much  curved.  A  sharp,  gently  curving  carina  extends  from  the 
umbo  to  the  posterior  angle  and  cuts  off  a  triangular  and  slightly  concave  area. 

Ornamentation  consists  of  fine  concentric  lines. 

Measurements  ; 


(1) 

(2) 

(3) 

Length 

25 

. 

23 

21  mm. 

Height 

17 

. 

14 

1-i'     „ 

Thickness 

, 

, 

IG 

, 

15 

15     „ 

(1- 

-3) 

Chalk  Kuck, 

Cuckliamslej. 

Affinities. — Wollemann  considers  that  Tra2)ezium  galicianum  (Favi'e)'  is  not 
distinct  from  this  species,  but  is  founded  on  an  older  example  than  tlie  type  of 
T.  lrfijie-:oi(l(il('.  According  to  Wollemann,  various  changes  in  the  form  of  the 
sliell  take  place  during  growth.  Thus,  iu  the  older  specimens  the  valves  become 
more  convex,  the  length  relatively  less,  the  posterior  margin  less  oblique,  the 
ventral  margin  more  curved,  the  outline  less  trapezoidal,  and  the  umbones  less 
curved.  This  view  is  probably  correct,  l)ut  none  of  the  English  examjjles  which  I 
have  seen  pass  beyond  the  stage  represented  by  Eomer's  type. 

Tn  Trape'Mim  tricarinatum  (Romer)'-  the  umbones  are  less  anterior  in  position 
than  in  T.  tvapczoidalc. 

1  '  Moll.  Foss.  de  la  Craio  de  Lemberg '  (l8l5!l),  p.  109,  pi.  xii,  tig.  3. 

-  '  Die  Versteiu.  d.  uord-deutseli.  Kreidegeb.'  (1841),  p.  74,  pi.  ix,  fig.  23. 


ISOCARDIA. 


151 


Bemarl:^. — This  species  occurs  in  the  f'halk  Rock,  l)iit  is  not  common.  All  the 
specimens  seen  are  casts,  but  one  shows  a  fragment  of  shell. 

Ti/pe. — The  type  is  stated  by  Romer  to  have  come  from  the  Pliiner-kalk  of 
Strohlcn  (Dresden),  but  Geinitz  says  that  he  has  never  found  the  species  at  that 
locality. 

BhtrihnHon. — Clialk  Rock  of  Dover,  Cuckhamsley,  Aston  Rowant,  Princes 
Risborough,  Thickthorn  Hill  (Bledlow),  and  TiUton  i-ail\v;iy  futting. 


i^.??H(7//— ISOCARDIIDJ^,  dray. 

Genus — Isocardia,  Lmnarch,  1709. 
('Mem.  Soc.  Hist.  Nat.  raris,'  p.  80.) 


Isocardia  similis,  Sowerhj,  1826.     Text-fig.  25. 


1826.     Isocardia  similis,  /.  de  C.  Sowerhy.     Min.  Conch.,  vol.  vi,  p.  27.  pi.  dxvi, 

fig.  1. 

—  A.  (VOrhujny.     Prodr.  de  Pal.,  vol.  ii,  p.  163. 

—  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  204. 

—  F.  J.  Pictet  and  G.  Campiche.     Foss.  Terr.  Crct.  Ste. 

Croix  (Mati'r.  Pal.  Suisse,  ser.  4), 
p.  240. 

—  F.  Slolicxl-a.     Palffiont.  Indica,  Cret.   Fauna  S.  India, 
vol.  iii,  pp.  188,  194. 


1850.  — 

1854.  — 

1865.  — 


1870.  — 


A 


f 


1 


•/  > 


v 


^ 


Fio.  2.x-/sr>fanJi<.  simxUt,  Sowerby.     Lower  Greonsnnd,  near  San.lRnlo.     KiKht  v.ilvo.  nn.l  anterior  view. 
British  Miisomii  (Nat.  Hist.).    Tlie  Typo.     NatunU  size. 


i:)2  CRETACEOUS   LAMELLIBRANCHTA. 

Drscrijdinn. — Slu'll  convex,  oval,  longer  than  high.  Antero-dorsal  margin 
short.  Anterioi-  margin  produced,  somewhat  pointed,  rounded,  curving  rapidly-  to 
join  the  slightly  convex  ventral  margin.  Posterior  margin  short,  somewhat 
truncated.  Postero-dorsal  margin  long,  convex,  with  a  considerable  ventral  slope. 
Umbo  prominent,  recurved.  Lunnlar  region  deep.  A  faint  carina  extends  from 
the  imibo  to  the  jiostero-ventral  extremity.  Ornamentation  consists  of  growth- 
lines.     Length  78  mm.     Height  70  mm. 

Bemnrlcs. — The  type,  a  right  valve,  now  in  the  British  Museum,  is  the  only 
undoubted  example  of  this  species  which  I  have  seen.  From  the  nature  of  the 
matrix  there  seems  no  doubt  that  this  specimen  comes  from  ihc  vniiiimilatitm  zone. 
The  hinge  cannot  he  made  out  satisfactorily,  l^ut  the  form  of  the  shell  agrees 
closely  with  that  typical  of  hocardia. 

Disfriliiition. — Lower  Greensand  (zone  of  BmiriUncoras  mammihitnm)  near 
Sandu'ate.' 


i^ar»%— LUCINIDiE,  Fleming. 
Genus — Lucina,  J.  G.  Brvtjuiere,  1797. 

('  Encyc.  Metli.,  Vers,'  pi.  odxxxiv.     Lamarck,  '  Mi'm,  Soo.  Hist..  Nat.  Paris,'  1799,  p.  84.) 


LuciNA,  sp.     Plate  XXIV,  figs.  2,  3. 

Internal  casts  of  a  Lucina  have  been  obtained  from  the  Spilsby  Sandstone 
(/.one  of  Bdemnitcs  latomli.^)  of  Donnington  and  Claxl)y.  A  right  valve  with  the 
shell  preserved  was  found  by  Mr.  Lamplugh  in  the  Spilsby  Sandstone  at  ITolton 
and  ])robably  belongs  to  the  same  sjiecies  as  the  casts.  The  shell  bears  numerous 
small  concentric  ridges. 


Lucina,  sp.     Plate  XXIV,  figs.  4,  5. 

Some  internal  casts  and  a  portion  nf    an  external  cast  of    Luciiin  have  been 

1  honiriVia  f  omnia,  Forbes,  'Quart.  Journ.  Geol.  Soc.,'  vol.  i  (1845),  p.  242,  pi.  ii,  fig.  10,  is 
Known  only  liy  Ibe  imperfect  typo  specimen  which  is  now  iu  the  Museum  of  the  Geoloi^ncal  Society 
(No.  21.')0),  ami  was  obtaine.1  from  the  Lower  Greensand  of  Alborfiolil.  It  was  roforrod  to  Ojiix  by 
•rOrbigny,  '  Prodr.  de  Pal.,'  vol.  ii  (1850),  p.  118. 

I.-dt-anlia  cryptocoraa,  d'Orbii^ny,  has  Itcon  recorded  by  BaiTois  from  the  Upper  (Jroousand  way 
Devizes,     Sec  'Terrain  Cn't.  suix'r.  dc  l"Anglelerrc  ct  .Ic  I'lrlande'  (187(')).  p.  61. 


LUCINA.  153 

foiiiicl  in  the  Lower  Greensaiur  nf  Blackgaug,  Shankliii,  and  I'liilunii  I'ark.  Tlie 
outline  is  nearly  circular  and  tlie  convexity  small  or  inoileratc.  The  ornamenta- 
tion consists  of  concentric  ribs  and  flat  interspaces. 

LuciNA,  sp.     Plate  XXIV,  fig.  G. 

A  specimen  witli  the  two  valves  united  was  ohfaincil  by  the  late  C.  J.  A. 
Meyer  from  the  Lower  Greensand  (Ferruginous  Sands)  of  Sliankbii,  and  appears 
to  Ijelong  to  a  distinct  species.  The  shell  is  regularly  convex,  slightly  higher  than 
long,  and  the  lunule  is  deeply  depressed.  The  ornamentation  consists  of  numerous, 
small,  regular,  concentric  ribs. 

LiTfixA?  scuLPTA,    Phillip.%  1820.     Plate  XXTV,  figs.  7—9. 

182D.     Lpcina  sculpta,  /.   Phillips.      Geol.  Yorks.,  j)}).  122,  170,  pi.  ii,  fiij;.   1-'. 

(p.  252,  C(l.  3). 
1844.         —  —A.  d'Orhi.jtiy.     Pal.  Frauy.  Terr.  Crct.,  v,.l.  iii,  p.  118, 

pi.  ccLxxxiii,  figs.  1 — 4. 
18.50.         —  —         E.  Eichwald.      Zeitschr.    d.    deutscli.    geol.    Gesollsch., 

vol.  ii,  p.  471. 
—  —  —  A.  cVOrbifjni/.     Prodr.  de  Pal.,  vol.  ii,  p.  118. 

18,54.         —  —         /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  208. 

1862.         —  —         J.  G.  Chenu.     Man.  de  Conchyl.,  vol.  ii,  p.  110,  fig.  .571. 

1866.         —  —         F.  J.  Fidet  and  G.  Campiche.      Foss.  Terr.  Cret.  Ste. 

Croix   (Mater.  Pal.    Suisse,   ser.   4), 
p.  291. 
1871.         —  —         F.    Stoliczka.      Palseout.  ludica,  Cret.  Fauna   S.    India. 

vol.  iii,  p.  252. 
100(1.         —  —         A.  Wollemann.    Die  Biv.  u.  Gastrop.  norddeutsch.  Gaults, 

p.  277. 

Description. — Shell  very  convex,  liighei'  than  long,  with  angular  outline. 
Antero-dorsal  margin  long,  concave.  Postero-dorsal  margin  long,  convex.  Angles 
occur  at  the  ventral  limit  of  the  lunule,  at  the  junction  of  the  anterior  and  ventral 
margins,  near  the  posterior  part  of  the  ventral  margin,  and  at  the  ventral  limit 
and    the    middle    of   the    escutcheon.     Umbones    high,  prominent,  sharp,  curved 

1  Liicina  arduennensis,  d"Orl)igny,  and  L.  Diqiiiiiam,  d'Orbiguy,  have  heeu  recorded  by  Toploy 
from  the  Lower  Greensand  of  the  Weald.  I  have  not  seen  any  specimens  which  could  l)o  ideutifie<l 
with  those  species.  Two  imperfect  left  valves  from  the  Lower  Greensand  of  Athertield,  now  in  the 
Museum  of  the  Geologi.'al  Society,  were  rcferre<l  hy  Forties  to  L.  glnhifoniils,  Ixnnierio.  Witlmut 
Letter  specimens  it  is  <lifficult  to  ■letermine  the  genus  to  which  Forl«>s'  six'cimens  iiclong.  See  Forl)e.<*. 
•Quart.  ,T..„n,.  Geol.  Soc."  vol.  i.  (1H1.5).  p.  240;  Leyjnerie.  'Mem.  Sw.  gcol.  de  France."  v..I.  v 
(1842).  p.  4,  pi.  iii,  fig.  8. 


VA  rRETACEOrS    T.A:\rELTJBRAXrHTA. 

anteriorly.  Ridges  extend  from  the  iinil)o  to  tlie  angles  at  the  margin  of  the 
valve;  the  parts  between  tlie  ridges  are  flattened.  Lnnule  Inrge,  ovate,  divided 
into  ail  inner  and  an  outer  part  l\y  a  ridge.  Escutcheon  wry  large,  consisting  of 
a  median  lanceolate  part  which  is  much  depressed  and  sejiarated  by  a  sharp  edge 
from  a  large  concave  outer  portion. 

Ornamentation  consists  of  broad  concentric  ridges  which  run  parallel  to  the 
margin  of  the  valve  and  end  abrupt!)^  at  the  hnude  and  escutcheon.  Ver}-  fine, 
sometimes  indistinct,  ribs  occur  on  the  ridges  and  interspaces. 

Affinities. — Lucina  sruljjfn  is  quite  unlike  any  other  Cretaceous  species.  Its 
angular  outline  and  large  concave  escutcheon  give  it  an  unusual  appearance. 
Externally  it  shows  some  resemblance  to  some  species  of  Thi/nsirfiy^  but  the  hinge 
and  adductor  impressions  are  at  present  unknown.  Stoliczka  regarded  it  as 
probably  a  true  Lucina. 

Jtemarlcs. — I  have  seen  only  four  specimens,  of  which  three  are  in  the  British 
Museum  and  one  is  in  the  Museum  of  Practical  Geology. 

Tijitc. — The  type  cannot  be  found.  It  is  stated  to  lia\e  come  from  the  Speeton 
Clay  (Pzone  of  nch'ninites  minimus). 

Pisfrihniion. — Lower  Gault  (Bed  vi)  of  Folkestone. 


Lucina  tenera  (Smrrrhi),  1S8G.     Plate  XXIV,  figs.  10—14. 

1836.     Venus  ?  tenera,  /.  de  C.  Sowerhi/.     Trans.  Gcol.  Soc,  ser.  2,  vol.  iv,  pp.  lit, 

335,  pi.  xi,  fig.  7. 
1854.         —  —      J.  Morru.     Cat.  Brit.  Foss.,  ed.  2,  p.  231. 

1865.  —  —       (?  Lucina),  F.  J.  Pictei  and  G.  Campiche.     Foss.  Terr. 

Crt't.  St^.  Croix  (Mati'r. 

Pal.Suisse,ser.4).p.l8P. 

1870.  —  —       (PCabtatis),  F.  ,S7o/.iV2/w.     Palwont.  lu.lica,  Cret.  Fauna 

S.  In.lia,  vol.  iii,  p.  160. 
1875.     Lucina         —       A.  J.JuJces-Brovme.    Quart.  Jouni.  Geol.  Soc,  vol.  xxxi.  p. 

300,  pi.  XV,  figs.  10—12. 

Description. — Shell  oval,  moderately  convex,  longer  than  liigh,  inequilateral, 
the  anterior  part  longer  and  higher  than  the  postei-ior  part.  Anterior  margin 
regularly  rounded,  passing  gradually  into  the  cui'ved  ventral  margin.  Posterior 
margin  somewhat  truncated,  forming  an  obtuse  angle  with  the  postero-doi'sal 
margin.  Uml)ones  of  moderate  size  with  a  slight  forward  curvature.  Lnnule 
elongate,  depressed,  limited  by  a  carina.     Escutcheon  large,  not  distinctly  limited. 

1  Axinvs,  Sowerln- ;  Cri/ptoihin.  T\\r\i'n. 


LUCINA.  1 


J-) 


(1) 

Length     . 

15 

Height      . 

14 

Thickness 

8 

(1) 

(5) 

12-5       . 

<.l 

n 

7'5 

— 

■i-5 

Ornamentation  consists  of  numerous,  regular,  strong,  concentric  ribs  which  become 
smaller  near  the  antcro-dorsal  and  postcro-dorsal  niai-gins. 
Measurements  : 

(2)  (3)        . 

1-i  .  lo  .  iz-o        .  \i       inin. 

12  .  11  . 

7         .  G-5      . 

(1—5)  Gault,  Folkestone. 

Aj)inities. — In  form  and  ornamentation  this  species  resembles  Jj.  Sanctai-Crucu, 
Pictet  and  Campiche,'  but  is  much  smaller  and  relatively  longer. 

Tijpc. — The  tj-pe  came  from  the  (Jault  of  Folkestone,  but  cannot  now  be 
found.  The  specimens  figured  by  Jukes-Browne  are  in  the  Setigwick  Museum, 
Cambridge. 

Distriljiiflua. — Gault  of  Folkestone  and  Black  Ven.  Cambridifc  Greeusand. 
Upper  Greensand  (zone  of  Scldeciibachia  rostrata)  of  Devizes. 


LuciXA  DoWNESr,  sp.  nov.     Plate  XXIV,  figs.  15  «. — r. 

Description. — Shell  oval  or  nearly  orbicular,  moderately  convex,  slightly  iiieijui- 
lateral,  longer  than  high,  postero-dorsal  part  compressed.  Anterior  and  ventral 
margins  rounded.  Posterior  margin  less  convex  than  the  anterior,  forming  an 
obtuse  angle  with  the  convex  postero-doi-sal  margin.  Umbones  of  moderate  size. 
Lunule  elongate.  Ornamentation  consists  of  numerous  regular,  coucentrie,  lamellar 
ribs  separated  by  broad,  flat  interspaces  with  fine  concentric  ribs. 

Measurements  : 

(1)  (2) 

Length         .         32         .         20  mm. 

Height         .         28-5      .         24     „ 

Thickness     .  14  —     ,, 

(1,  2)  Blackd.iwii. 

AlJiuillrs. — This  species  resembles  L.  ('iiniiirli,nui.,  d'Orbigny,'  \'ix>n\  the 
Neocomiaii,  Imt  the  undjones  are  less  prominent  and  the  shell  is  less  iiRMHiilateral. 
It  is  also  similar  to  L.  submimismalis,  d'Orbigny,'^  from  the  Aachen  Greensand, 
l)ut  the  ribs  are   more    numerous  and  the    antero-dorsal    margin    has   a   greater 

'  "  Terr.  Crt't.  Ste.  Croix"  ('  Mater.  Pal.  Suisse,"  ser.  -4,  18tJG).  p.  28;t,  pi.  cxxii,  fig.  8. 

2  '  Pal.  Fi-au9.  Terr.  Crct.,'  vol.  iii  (1844),  p.  110,  pi.  cclxxxi,  figs.  3—5. 

•*  Holzapfel.  "  Die  MoUusk.  Aacheu.  KreiJe "  ('  PalsEoutographica,'  vol.  xxxv,  1880),  p.  187. 
pi.  xix.  figs.  1—3.  Eavn,  '  Mollusk.  i  Daumarks  Kridtafl.  I.  Lamellil.r.'  (PJ02),  p.  12!i,  [.l.  iv. 
tiu'.  21. 


lOG  CliK'l'ACL'^OLS    LA.M  KI.LI  IJIi  ANCHIA. 

vt'iili'al   slii|R'.      TIk'   ribs  arc   iiioiv   iiuiiicrdus  lliaii    in   Lncin((   Xrrcis,  d'Orljigu}',^ 
I  vmw  t  lir  (V'lioiiiaiiiaii. 

I'islribittidu. — Uppor  Greciisaiid  (zone  of   Scltlirulincliiii  nistfdfn)  ol'  IJlacktlowii. 
Up[)er  Greensaiul  near  Ijyiiie  Regis. 


LuciNA  I'lSU.M,  Soircrlii/,  ]S'M>.     Plate  XXIV,  figs.  ](J — !',•. 

1836.     LuciNA   I'isuM.  /.  ih  C.  Sowirhij.     Traus.  Cleol.  Soc,  ser.  i,  vul.  iv,  iip.  241, 

a-11.  1)1.  xvi.  fig.  14. 
1850.  —  —       A.  d'Orhlyiii/.     I'milr.  <k'  Pal.,  vol.  ii.  p.  l(i-2. 

1854.         —  —J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  208. 

1871.         —  —      F.  Stolivzlai.      Palauout.  ludica,  Cret.  Fauua  8.  India,  vul. 

iii,  p.  252. 

Noll  1814.         —  —       A.  d'Orhiijnij.     Pal.  Fi-au9.  Terr.  Cret.,  vol.  iii,  pi.  L-cl.\.\xi, 

figs.  3 — 5  {L.  Cornuvliana,  p.  llli). 
r — 1868.         —  —      A.  Brlarl  iiikI  F.  L.  Cornet.     Meide  de  Bracqueguies  (Mem. 

cour.  et  Mi'Ui.  des  Sav.  utraugers,  vol. 
xxxiv),  p.  69,  pi.  viii,  figs.  18 — 21. 

Dcacriptioii. — Sliell  .small,  verj^  convex,  with  nearly  circnlar  outline,  slightly 
ine(|uilateral ;  length  and  height  nearly  ecpial.  Anterior  and  ventral  niargin.s 
forming  a  regular  curve ;  posterior  margin  slightly  truncated,  forming  an  obtuse 
angle  with  the  postero-dorsal  margin.  Umbones  rather  large.  Lunule  ovate, 
broad,  depressed.  Escutcheon  indistinctly  limited.  Ornamentation  consists  of 
concentric  ribs,  with  "Towth-rinas  at  intervals. 


»_11  LliV,        X±t_7.Z>j        **J.LJll       i;i»_'>*     Lll 

lllI^O       ClU       IIILV. 

_  I     *    tl  JC* 

\Ieasnrcm('iiti< : 

(1) 

(^) 

(:') 

Length 

5 

4-5 

!■    mm. 

Height 

4- 9 

4-;J 

4      „ 

Thickness 

:3-5 

3 

2-!)   „ 

(1—3)  Blackdowu. 

li'tiiiarls. — The  form  referred  to  L.  jjmtin  by  Briart  and  Cornet  is  ninch  larger 
llian  the  English  exam])les  of  that  species,  and  also  differs  in  its  relatively  longer 
and  more  compressed  shell. 

Ti/j)r. — From  Blackdown  ;  in  the  Bristol  Museum. 

Di.'i/riliiitioii. — Upper  (jreensand  (/.one  of  Sclihriiliitclun  rosti-ntn)  of  Blackdown. 

1  Trodr.  de  Pal.,'  vol.  ii  (IS.W),  p.  162.  Gu.'-raugvr,  'Alhuiii  Pal.'.mt.  du  la  SaHlie"  (1867), 
p.  12,  [il.  XV,  fig.  15.  The  hinge  figured  by  Gut'ranger  does  not  agree  with  Liiclna.  Stoliczka  suggests 
that  this  species  belongs  to  (Jijprimeria,  see  '  Palieont.  Indica,  Cret.  Fauna  S.  India'  (1871), 
pp.  164,  253. 


SPHiERA.  157 


■  Geniis — CoRHif'ELLA,  J.  Morn's  'iinl  J.  Li/rrtf,  185:"!. 
('Moll.  Great  Ool.,'  pt.  ii,  p.  04) 

COEBICELLA  0LAXI3IENSIS,  sp.  iiov.      Plate  XXIV,  figs.  20 — 28. 

Descri2}tion. —8he\l  oval,  regularly  convex,  sligLtly  inequilateral,  anterior  part 
ratlier  larger  than  the  posterior  part,  length  equal  to  nearly  1^  times  the  height. 
Anterior  margin  rounded.  Ventral  margin  convex,  curving  rapidly  to  join  the  pos- 
terior margin  which  fatms  an  angle  with  the  nearly  straight  postero-dorsal  margin. 
Umbones  broad,  inconspicuous,  scarcely  curved,  close  together.  Surface  of  shell 
smooth  except  for  growth-lines. 

Measurements  : 

(1)  (2)  (3)  (I) 

Length         .         38         .         37         .         30         .         27  mm. 
Height         .         26         .         25         .         21         .         19     „ 
(1 — 4)  Claxby  Ironstone,  Bcnniworth  Haven. 
Remarlcs. — The  genus  Corbicella  does  not  appear  to  have  been  recognised  in 
deposits  of  Cretaceous  age,  but  since  it  is  present  in  tlic  Portlandian  its  occurrence 
in  the  lower  part  of  the  Speeton  Series  of  Lincolnshire  causes  no  surprise. 

0.  claMensis  is  similar  in  outline  to  some  forms  of  G.  Pcllati,  dc  Loriol,'  from 
the  Portlandian. 

Type. — In  the  Sedgwick  Museum,  Cambridge. 

Disfrihufion. — Spilsby  Sandstone  (zone  of  Belomnites  lateralis)  of  Claxby  and 
Donnington.     Claxby  Ironstone  (zone  of  B.  lateralis)  of  Benniwoith  Haven. 

Genus— iivuA:T..\,  J.  Hoircrhi/,  1822. 
('Min.  Conch.,'  vol.  iv,  p.  41.) 

SrajiiiA  coiiiirGATA,  Scm-crh;/,  1822.     Plate  XXIV,  fig.  24;  Plate  XXV,  figs.  1,2; 

text-fig.  2(3. 

1822.     Sm^TiKA  CORRTJGATA,  J.  Sowcrhy.     Min.  Concli.,  vol.  iv,  p.  42.  pi.  cccxxxv. 
1842.     Venus  cordiformis,  A.  Lcyweric.     Mrm.  Soc.  gcol.  dc  Fi-ancc,  ser.  2.  vol. 

v,  p.  .5,  pi.  v,  fig.  8. 

'  De  Loriol  and  Pellat,  '  Jui-ass.  de  Boulognc-sur-mer '  (1875),  p.  67,  pi.  xiv.  fig.  12. 

21 


ir.S  rRETATEOFS    LAMELLTBRANCHIA. 

1842.     Cakdium  oallopeovinciale,  P.  Maihcron.     Catal.  Poss.  du   Depart,  des 

Bouclies-du-Rhone,  p.  155, 
pi.  xvii,  fi<,'.s.  1,  2. 

1844.  CoRBis  conDiFORMis,  A.  iVOihiijiiij.     Pal.  Frau9.  Terr.  Crut.,  vol.  iii,  p.  Ill, 

pi.  cclxxix. 

1845.  —       COEEUOATA,  E.  Forhes.     Quart.  Journ.  Geol.  Soc,  vol.  i,  p.  239. 
1850.        —  —         cVOrhifjny.     Prodr.  de  Pal.,  vol.  ii,  p.  78. 

1854.     Sph^ea  —         J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  224. 

1865.     Cordis  —         G.  CoUeau.     Moll.  Foss.  de  I'Yonne,  p.  80. 

185G.         —  —F.J.  Pldd  nmJ  E.  Renevicr.    Foss.  Terr.  Aptien  (Matrr. 

Pal.  Suisse,  ser.  1),  j).  7(5,  pi.  viii, 
fig.  3. 
1859.         —       coEDiFOEMis,  /.  Vilanova-y-Plera.     Mem.  geog.-agric.  de  Castellon, 

pi.  iii,  fig.  13. 
18G5.         —       coERUOATA,  H.  Coqnand.     Mou.  Aptien  de  I'Espagne,  p.  IIG. 
18CC.     FiMBEiA  —         F.  J.  Picfet  and  G.  Campiche.     Foss.  Terr.  Crc't.  Ste. 

Croix  (Mater.  Pal.  Suisse, 
ser.  4),  p.  279. 
18G9.     Pal^ocoebis  coedifoemis,  T.  A.  Conrad.     Amer.  Jouru.  Coucli.,  vol.  v, 

p.  101. 
1871.     SiMLTiRA  coREUQATA,  F.  SloliczJca.     Palooout.  ludiea,  Cret.  Fauna  S.  India, 

vol.  iii,  pp.  247,  252. 
V  1877.     CoEBis  ef,  COERUOATA,  G.  Bolim.     Zoitschr.  d.  deutscli.  geol.  Gesellsch.,  vol. 

xxix,  p.  240. 
1897.        —       coEEtTGATA,  7v.  Gerhavdt .     Neues  Jalirb.  fiir  Min.,  etc.,  Beil.-Bd.  xi, 

p.  186. 
1899.     Fimbria        —        A.  WuJlcmann.     Zeitschr.  der  deutscli.  geol.  Gesellsch., 

vol.  li,  p.  592. 

Description. — Shell  large,  stout,  inflated,  subglobular,  slightly  inequilateral, 
height  and  length  nearly  equal.  Anterior  margin  rounded,  forming  an  angle  with  the 
hinge-margin,  and  passing  gradually  into  the  ventral  margin  with  which  it  forms 
a  regular  curve.  The  ventral  margin  curves  rapidly  towards  the  posterior  margin, 
Avhich  makes  an  obtuse  angle  with  the  hinge-margin.  Lunule  flattened  or  depressed, 
with  a  swollen  lower  margin  which  is  separated  from  the  rest  of  the  valve  l)y  a 
furrow.  Escutcheon  triangular,  limited  by  a  furrow  which  passes  from  the  umbo 
to  the  posterior  margin.  Umbones  large,  ])rominent,  ciu'ved  anteriorly'.  Ornamen- 
tation consists  of  broad,  strong,  unequal,  concentric  ridges  which  arc  more  numerous 
on  the  middle  than  on  the  anterior  and  posterior  parts  of  the  shell.  The  concentric 
ridges  are  crossed  l)y  numerous,  small,  radial  ril)s. 

Measurements : 

(1)  (2)  (3)  (4) 

Ecnglh         95         .         84         .         80         .         70  mm. 
Heiglit  93         .         8:3        .         77         .         G8     „ 

(1 — 4)  Lower  Greeiisninl,  Atlierficld. 


SPII^RA. 


150 


Remarlx. — This  species  is  tlio  type  of  the  genus  Sjihmru.  Tt  is  fairly  coiiiiikhi 
in  the  Ferna-hed  of  the  Isle  of  Wight.    A  young  example  is  figured  by  d'Orhigny. 

Ti/pr. — The  type  was  obtained  by  Professor  Sedgwick  from  the  7V/-y(((-bed  of 
Sandown,  but  cannot  now-  1)0  found. 


Fiu.  2ij.—t>phxra  con-wjala.   Sow.     Lower   GroensanJ,  iioiu-   Ilythe.     Miisoiuu   of  I'nictical  Guology, 

No.  I'JTIG.     Dorsal  view,      x  -J. 

Bidriblllioll.—Lo^ycr  Greensand  {I'cnia-hcd  and  Crackers)  of  Alherlield  ;  also 
recorded  by  Fitton  from  Beds  viii  and  xiv,  Hythe  Beds  of  Hythe  and  Maidstone. 
Eecorded  by  Topley  from  the  Atherfield  Beds  of  Peasmarsh  and  Shalford ;  the 
Hythe  Beds  of  Lympe ;  and  the  Sandgate  Beds  of  Sandgate.' 


Si'UJiiiA,  sp.     Plate  XXV,  fig.  'S. 

A  small  specimen  from  the  Chalk  ^Marl  of  Clmrd  appears  to  l)elongto  a  distinct 
species.  It  is  much  smaller  than  S.  covriKj'dii,  also  relatively  longer,  more  ovnl  m 
outline,  and  less  inflated.  The  escutcheon  is  not  defined,  the  lunule  is  small  or 
absent,  and  the  antero-dorsal  margins  are  thick  and  prominent.  The  concentric 
ridges  resemble  those  of  8.  cornniala,h\.\ii\iQ  radial  ribs  are  more  distinct.  Length 
IG'5  mm. ;  height  14  mm. ;  thickness  12'5  mm. 

1  The  type  of  Corhis  ?  fibrosa,  Forbes,  from  Peasmarsh,  is  in  tlie  Museum  of  the  Geolo^'ical 
Society  (R  215-1),  but  is  too  imperfect  for  deteriniuatiou.  Forbes,  'Quart.  Jouru.  Geol.  Soc.."  vol.  i 
(184.5),  p.  239. 


ICO  CRETACEOUS   LAJilELLlliKANCHIA. 


0'c'M(«— MUTIELLA,  Slulic::lca,  1871. 
('Palaeout.  ludica,  Cret.  Fauua  S.  India,'  p.  247.) 

MuTiELLA  ?  CANALICULATA  (Sowerbi/),  183G.     Plate  XXV,  figs.  4 — G. 

1836.     Peteicola  canaliculata,  /.  de  C.  Sowerby.     Trans.  Geol.  Soc,  sor.  2.  vol. 

iv,   pp.    241,   341,   pi.  xvi, 
fig.  11. 

—  —  NUCiFOEMis,  Sowcrhij.     liiitl,  pp.  241,  341,  pi.  xvi,  lig.  lU. 
1850.     Cakdium  canaliculatum,  A.  d'Orhiijnij.     Prodr.  de  Pal.,  vol.  ii,  j).  1(J3. 

—  —         NUCIFOKME,  d'Orhijni/.     Ibid.,  p.  163. 

1854.     Petkicola  ?  canaliculata,  /.  Morris.     Cat.  Brit.  Fuss.,  ed.  2,  p.  220. 

—  —  NUCIFOEMIS,  Morris.     Ibid.,  p.  220. 

1866.     Caedium  canaliculatum,  F.  J.  Pictet  and  G.  Campic/ii;.     Foss.  Terr.  Crct. 

Ste.    Croix    (Mater.    Pal. 
Suisse,  ser.  4),  p.  270. 
1865-6G.     Petkicola  nucifoumi.s,  Pictet  and  Campiche.     Ibid.,  pp.  163,  276. 
1870.  —  canaliculata  (Caedium),  F.  UtoIiczJca.      Palajout.   ludica, 

Cret.  Fauna  S.  India,  vol. 
iii,  p.  141. 

—  —  NuciFoKMis  {'f  CoKBis),  StolicxJia.     Ibid.,  p.  141. 

Description. — Shell  iiiHated,  outline  mure  or  less  orbicular,  hie(juilateral,  length 
and  height  eciual.  Margins  rounded,  xlnterior  margin  less  convex  than  the  pos- 
terior margin.  The  latter  makes  an  obtuse  angle  with  postero-dorsal  margin  and 
curves  rapidly  to  join  the  ventral  margin.  The  margin  in  front  of  the  umbo 
expands.     Umboues  large,  contiguous,  curving  inward  and  forward.     No  lunule. 

Ornamentation  consists  of  numerous,  regular,  radial  ribs,  separated  by  narrow 
furrows,  and  crossed  l)y  narrow  concentric  ridges  which  ai'c  more  prominent 
on  the  posterior  part  of  the  shell  than  elsewhere.  Inner  margins  of  the  valves 
crenulate. 

There  are  two  cardinal  teeth  in  the  left  valve  and  one  in  the  right.  Behind 
the  umbo  a  long,  nearly  straight,  sharp  ridge  forms  the  inner  margin  of  the 
ligament  groove. 

Measurements  .- 

(1)  (-')  (a) 

Length  .         20-5        .       I'J       .       17 

Height  .         20-5        .       19       .       17       . 

^1—4)  Blackdowu. 
Affinities. — The   generic   position   ol'   this  species  has  been   for   a  long  time  a 
matter   of   doul)t,   l)ut    no   one   appears   to   have  accepted   Sowerl)y's  view.      The 


(I) 

1-1-5     . 

]()  mm 

14-5     . 

10     „ 

MUTIELLA.  Kil 

species  is  rare,  and  the  opinions  expressed  by  various  authors  appear  to  have  Ijeeu 
based  entirely  on  the  figures  given  by  Sowerby. 

The  hinge  is  similar  to  that  of  MutielUi  coarctata  (Zittel),'  but  shows  some  i)oints 
of  difference  :  thus  the  transverse  corrugations  or  teeth  on  the  expanded  anterior 
margin  appear  to  be  absent,  and  the  terminal  posterior  lateral  tooth  cannot  be 
recognised  with  certainty.  The  points  of  resemblance,  however,  and  the  similarity 
in  the  form  of  the  shell  and  the  character  of  the  ornamentation  seem  suflicient 
to  justify  the  assignment  of  this  species  either  to  Mafielhi  or  to  a  closely 
allied  genus. 

From  the  figures  given  by  Sowerby,  Petiicola  unc'ifortim  appears  to  differ  con- 
siderably from  P.  cdiiallcnlata,  but  after  an  examination  of  the  type  of  the  former 
I  am  led  to  the  conclusion  that  it  is  not  specifically  distinct  from  the  latter ;  it 
differs  only  in  being  more  inequilateral,  and  the  apparent  difference  in  the  uiiia- 
mentation  is  due  to  the  imperfect  preservation  of  the  surface  of  the  shell  in 
1'.  )iiicifoniiis. 

Tii[ics. — From  Blackdown.  The  type  of  J'ctricukt  caiudicniata  cannot  be  found. 
The  type  of  P.  nuclj'ormls  is  in  the  Bristol  Museum. 

DistribHtioii. — Upper  Greensand  (zone  of  Scldamhacldd  rostrala)  of  Blackdown, 
and  Peak  llill,  near  Sidmouth. 


MuTiiiLLA  larrrxMATA  {(rOrhiijin/),  1 8^1-4. 

1844.     Coums  ROTVSBXTA,  A.  d'Oihi(jinj.     i'ul.  Fium;.  Terr.  Cix't.,  vol.  iii,  \>    Ilo, 

pi.  cclxxx,  figs.  1— i. 
1850.         —  —  —  Prodi-,  de  Pal.,  vol.  ii,  p.  1(32. 

18G7.         —  —  E.   Gtiiramjcr.      Album  Piilcout.  do  la  Sarthe,   p.   15, 

pi.  six,  figs.  lU,  11. 

1870.  —  F.  Itinner.     Geol.  v.  Obersdiles.,  p.  3i0. 

1871.  MuTiELLA  KOTUNUATA,  F.  StoUczkci.     Palujout.  liidica,  Cret  Fauua  S.  ludia, 

vol.  iii,  pp.  247,  252. 
1896.     CoEBis  KOTUNDATA,  A.  J.  Jukes-Broione  and  W.  Hill.     Quart.  Joiu-u.  Geol. 

Soc.,vol.  lii.p.  153. 

A  portion  of  a  right  valve  of  MiUicUa  rotuiulata  from  the  Ccuomanian  (Bed  11) 
of  Dunscombe,  South  Devon,  was  found  and  determined  by  the  late  C.  J.  A. 
-Meyer.  An  internal  cast  was  collected  from  Bed  10  of  Beer  Head  by  Mr.  Jukes- 
Browne,  who  also  records  the  species  from  the  Chloritic  Marl  of  Maiden  Bradley, 

'  Fimbria  coarctata,  Zittel,  '  Die  Biv.  d.  Gosaugeb.,'  pt.  i  (1864),  p.  44,  pi.  vii,  tig.  5.  Kt-fonvd  bv 
Stoliczka,  aud  subsecjueutly  by  Zittel  aud  by  G.  Miiller,  to  the  genus  MutielUi.  Compare  also  the 
hiugeof  Mutiella  ruttindata  figured  by  Guerauger,  'Album  Pak'out.  de  la  Sarthe'  (1867),  pi.  xix, 
fig.  11. 


I'i2  CRETACEOUS    LAMELTJBRAXCTTTA. 

and  the  Cliulk  Mini  of  Chard.     The  specimens  seen  are  nut  sulHciently  perfect  for 
fiii^urinij. 

M.  rotwudata  is  the  type  of  the  genus  Matiella.     In  France  this  species  is  i'uiuid 
in  the  Cenomauian  of  Le  Mans,  Sarthe,  Rouen,  etc.^ 


i'^amiVy— UNICARDIID.E,  Fisrh <,: 

Genus — Unicaedium,  .1.  iTOrhhjuij,  18i*,). 
(•rruilr.  do  Pill.,'  vol.  i,  p.  -218.) 

Unicakhhm  (  laxciense,  sp.  nov.     Plate  XXV,  figs.  7  a,  l>. 

JJencriptiuii. — Sliell  kxrge,  oval,  inflated,  witli  somewhat  flattened  sides,  very 
inefjuilateral ;  anterior  jjart  much  longer  than  posterior  part.  Anterior  margin 
WL']]  rounded,  passing  gradually  into  the  antei'O-dorsal  margin,  and  into  the  ventral 
margin,  which  is  only  slightly  curved.  Posterior  margin  truncated.  Umbones 
broad,  curved  inward  and  slightly  forward.  In  front  of  the  unil)ones  the  shell  is 
dej)ressed . 

Ornamentation  consists  of  narrow,  sharp,  prominent,  somewhat  irregular  con- 
centric ribs  separated  by  relatively  broad,  concave  interspaces. 
Measurements  : 

(1)  (a) 

Length         .  .  52  .  40  mm. 

Height         .  .  45  .  34     „ 

(1,  2)  Bfuuiwortla  Haveu. 

Affinities. — In  this  species  the  umbones  are  not  so  high  ami  the  posterior  part 
of  the  shell  is  longer  than  in  U.  Iteterai'lifiim  (d'Orbigny)- ;  also  the  ril)s  appear  to 
be  narrow  and  sharper. 

Type. — In  the  Sedgwick  Museum,  Cambridge. 

Distrihntion. — Claxl)y  Ironstone  (zone  of  llclciiniitc.s  lutrrnlis)  of  Benniworth 
Haven,  Lincolnshire. 


') 


'  Corbis  ?  Morisoni,  Woods,  from  the  Chalk  Rock  of  Cuckhamsley,  is  at  present  knowni  by  two 
iiuperfoct  valves  only.  The  hiuge  cannot  l)e  seen,  and  the  generic  position  of  the  species  is  still 
uucortain.     See  Woods,  '  Quart.  Journ.  Geol.  Soc.,'  vol.  liii,  p.  392,  pi.  xxviii,  figs.  13,  14. 

-  In  Murchison,  de  Verneuil  and  de  Keyserliug,  '  Gt'ol.  Russie  de  I'Europe,'  vol.  ii  (1845),  p.  460, 
pi.  xxxix,  figs,  n,  10.  D'Orhiguy,  '  Prodr.  de  Pal.,'  vol.  i  (1840).  p.  367.  Eichwald,  '  Lethiea  Rossica,' 
vol.  ii  (1868),  p.  647.  Two  examples  of  U.  heteruclitum  from  the  Lower  Volgian,  near  Moscow,  are  in 
Mr.  Lamplugh's  collection. 


UNICARDIUM.  10:3 

Unicardium  vectense,  sp.  nov.     Plate.  XXV,  figs.  8—11. 

BcscripHon. — Shell  thin,  much  inflated,  oval  or  slightly  subquadratc,  inequi- 
lateral, the  anterior  part  rather  larger  than  the  posterior  part;  length  a  little 
greater  than  height.  Antero-dorsal  margin  short,  nearly  straight.  Anterior 
margin  rounded,  making  an  obtuse  angle  with  the  antero-dorsal  margin,  and 
curving  rapidly  to  join  the  moderately  convex  ventral  margin.  Posterior  margin 
rounded,  slightly  truncated.  Postero-dorsal  margin  slightly  convex.  Umbones 
prominent,  contiguous,  cur^ang  inward  and  forwainl.  Ornamentation  consists  of 
numerous,  strong,  somewhat  irregular,  concentric  ribs.  Ligament  in  a  long, 
narrow  groove.     Teeth  absent  or  poorly  developed. 

Measurements  : 

(1)  (2)  (;5)                     (4) 

Length     .         20  .         18  .         10  .         12      mm. 

Height     .         19  .         17  .         15                  11-2     „ 

(1 — 4)  Crackers,  Atlierfiekl. 

Affinities. — The  shell  is  relatively  higher,  the  umbones  more  prominent,  and 
the  rilis  rather  stronger  than  in  F.  Ebra/ji,  de  Loriol.^ 

Distnbntion. — Lower  Greensand:  Crackers  of  Atherfield,  Perna-hed  of  Sandown, 
and  Ferruginous  Sands  of  Shanklin. 


TJnicardium,  sp.     Plate  XXV,  fig.  12. 

A  specimen  of  rnicardiitm  Ironi  the  LTpper  Greensand  of  South  Devon- was 
collected  by  Sir  H.  T.  De  la  Beche  and  is  now  in  tlie  Museum  of  the  Geological 
Society,  No.  1580.  It  resembles  U.  vectense,  but  the  umbones  are  not  so  promi- 
nent and  the  ribs  are  .smaller,  more  numerous,  and  more  regular. 


Uxii\\i;nirM  ?  oauitixim  {Pii'td  and  Rovx),  1852. 

1852.     CoRBLS  GAULTiNA,  F.  J.  Piclct  anil  W.  Rout.     Moll.  Foss.  Gris  verts  ilc 

Geneve,  p.  448,  pi.  xxxiv,  fif;.  4. 
1866.     Fimbria       —         F.  J.  Pidet  and  G.   Campiche.     Foss.   Terr.   Crct.  Ste. 

Croix    (Mater.  Pal.    Suisse,   ser.   4), 
p.  282,  pi.  cxxii,  figs.  3,  4. 
1871.  —  —         F.   Sfolirzl-a.      Pala?out.  Indica,  Cret.   Fauna   S.    Iiulia, 

vol.  iii,  p.  2.52. 
1875.     CoRBis        —         A.  J.  Jidcs-Broicne.     Quart.  Jourii.  Geol.  Sec.,  vol.  xxxi. 

p.  300.  pi.  XV,  fig.  9. 


1  '  Gault  de  Cosnc'  (1882),  p.  70,  pi.  viii,  figs.  13-16. 
-  Probablv  from  near  Siilinontli  or  Bluckdciwii. 


164  CEETACEOITS   LAMELLIBRATsTHIA. 

Two  internal  casts  from  tlio  C'amljridge  Greensancl  (derived  from  the  Gault) 
were  identified  l)y  Mr.  Jukes-Browne  as  Cnrhis  f/duUina,  Pictet  and  Roux.  Tlie 
specimens  are  in  the  Sedgwick  Museum,  and  no  other  examples  appear  to  have 
been  Connd.  The  t.yp(>  of  ('.  (/inilfiiia  came  from  the  Gault  of  Saxonot.  In 
external  I'nrm  tliis  species  agrees  closely  with  VmranVvim,  hiif  llic  liiiige  is 
unknown,  so  (lint  the  generic  position  cannot  be  determined  with  certainty. 


Unicakptum  iMNriMEKiRNSE  {MunlcII),  1822.     Plate  XXV,  figs.  13,  14. 

1822.     Venus?  rinomekiensis,  G.  Mantell.     Foss.  S.  Downs,  p.  126.  pl.xxv,  fig.  5. 
18.50.     Panop;ea  —  A.  cVOrhujny.     Prodr.  do  Pal.,  vol.  ii,  p.  1-57. 

IS.'J-t.     Unicardium  rinOtMERIENSE,  J.  Morris.     Cat.  Brit.  Foss.,  cd.  2,  p.  229. 
1865.     Cardium  —  F.J.  rirti'l  find  G.Campiehe.     Foss.  Terr.  Cn't. 

Ste.  Croi.v  (Mater.  Pal.   Suisse, 
sor.  4),  p.  195. 
Nou  1^50.     Arca  ringmerensis,  II.  B.  Gcinitz.     Das  Quadorsandst.  oder  Kreidegeb.  in 

Dentscliland,  p.  162. 

—  1872.     MuTiELi.A  RiNOMERENRis.  Tf.  B.  Gcinlt-..     Das  Elbthalgeb.  in  Saclison  (Pal- 

oeoutographica,  vol.  xx,  pt.  2), 
p.  61,  pi.  xvi,  figs.  11-13. 

—  1877.  —  —  A.  FrUfrh.     Stud,  im  Gebiotc  der  bolini.  Kroido- 

format.  II  Woisseuberg.  w.  Maluitz. 
Schicht.,  p.  115,  fig.  75. 

—  1883.  —  —  FriUcli.     Ibid.  Ill  Iserschicht.,  p.  100,  fig.  64. 

—  1889.  —  —  Fritsch.     Ibid.  lY  Teplitz.  Schicht.,  p.  78. 

—  1807.  —  —  Friiscli.     Ibid.  VI  Chlomek.  Schicht.,  p.  54,  fig.  59. 

Descnj^tion. — Shell  subquadrate,  rounded,  inflated,  antero-dorsal  part  com- 
pressed, length  rather  greater  thaji  height,  inequilateral,  anterior  j^art  larger  than 
the  posterior  part.  Antero-dorsal  margin  nearly  straight.  Anterior  margin 
moderately  convex,  making  an  obtuse  angle  with  the  antero-dorsal  margin  and 
curving  rapidly  near  the  ventral  margin.  The  latter  is  moderately  convex  and 
curves  upward  to  join  the  posterior  margin,  which  is  slightly  cuiwed,  and  forms 
an  obtuse  angle  witli  the  postero-dorsal  margin.  Umboncs  large,  ])roinin('Tit, 
contiguous,  ciu'ving  forward.  Ornamentation  consists  of  strong,  narrow,  con- 
centric ridfjes. 


Mcasnrevienfff  : 

(1) 

(a) 

Length     . 

42 

.■ICi  nnu. 

TTeight      . 

38 

(Ij  Clialk  Marl,  Titherlcigh. 
(2)  Chalk  Marl,  Chardstoek. 

■u  „ 

THETIRONIA.  165 

Remarl's. — Tlie  spt'ciniens  from  tlie  Plant-r-kalk  of  Strelilen  which  were 
referred  to  this  species  by  Geiiiitz  appear  to  be  related  to  Mutiella  coarctata 
(Zittel).i 

Ti/pe. — The  type  came  from  the  Chalk  Marl  of  ]\liddleham,  hnt  cannot  now  be 
found. 

Distrihution . — Upper  Greensand  (zone  of  Schlmnharlna  rostrata)  of  Devizes. 
Base  of  Chalk  Marl  of  Titherlcigh  and  Chardstock.  Chalk  Marl  of  Middleham 
and  Rino'mer. 


[Systematic  position  not  determined.] 
Genus — TnETiKONiA,  F.  Stolicd-a,  1870. 

('  Palaeont.  Indica,  Cret.  Fauna  S.  India,'  vol.  iii,  p.  1-58.  Thetis,  J.  do  C.  Sowerb_v,  '  Min.  Concli.,' 
vol.  vi,  182G,  p.  19.     Non  Thetis,  Oken,  1815.     Svn.  Fimbnella,  Stoliczka,  op.  cit.,  p.  24G.) 

The  genns  Thetironia  \^T]ictis~\  has  been  placed  in  the  family  Vencridte  by 
Deshayes,  d'Orbigny,  Chenn,  Stoliczka,  Zittel,  Fischer,  Dall,  and  other  authors,  on 
account  of  the  presence  of  the  acutely  angular  line  which  has  often  been  regarded 
as  a  pallial  sinus.  This  angular  line  appears  as  a  deep  groove  on  internal  casts, 
and  must  consequently  have  been  a  prominent  rib  on  the  interior  of  the  shell.  In 
its  position  and  rib-like  form  it  is  fpiite  unlike  the  pallial  sinus  of  any  lamellibranch,- 
and  it  seems  to  be  a  structure  of  an  entirely  different  nature,  probably  serving,  as  was 
suggested  hj  S.  P.  Woodward  ^  merely  to  strengthen  the  thin  shell.  Thetironia  is 
fui-ther  distinguished  from  the  VeneridtB  by  its  hinge,  which  is  of  quite  a  different 
typo  (see  Plate  XXVI,  figs.  10/;,  14).  Stoliczkii,  in  referring  this  genus  to  the 
Veneridae  and  sub-family  Dosiniinfe,  says :  "  There  can  be  little  doubt 
that  all  the  external  characters  indicate  a  close  appproach  to  the  recent 
dementia  " ;  the  hinge,  however,  which  seems  to  have  been  unknown  to  Stoliczka, 
shows  that  this  view  of  the  relationship  of  Thetironia  cannot  be  maintained. 

A  concentric  ridge  seen  near  the  ventral  margin  on  some  internal  casts  of 
Thetironia  has  been  regarded  by  some  authors  as  evidence  of  a  simple  jiallial  line ; 
but  the  presence  in  some  specimens  of  several  similar  ridges  at  different  distances 
from  the  margin  suggests  that  they  are  really  of  the  nature  of  growth-rings  (see 
Plate  XXVI,  fig.  G). 

Thetironia  was  identified  with  Poromya  by  S.  P.  Woodward  (1854)  and  by  IT. 

1  G.  Muller,  'Mollusk.  Untersen.  v.  Braunschweig?  u.  Ilsede'  (1808),  p.  GO. 

5  De  Loriol  compared  it  with  Lucinopsis,  hut  the  differences  between  the  pallial  sinus  of  that  genus 
and  the  angular  rib  of  Thetironia  are  consideiwble. 

s  'Manual  of  the  Mollnsca,"  ed.  1  (18.M),  p.  310;  od.  3  (IS?.--.),  p.  401.  Woodward  says. 
"  umViones  strengthened  insiile  by  a  posterior  lamina.  " 


ICG  CRETACEOUS   LAIHELLTBRAXCHIA. 

and  A.  Adams  (lSr)R).  Bosliayes  (1858),  and  Pictet  and  Campiche  (18G5), 
though  considering  tlieni  allied  forms,  did  not  regard  them  as  generically 
identical.  The  latter  authors  had  little  confidence  in  the  suggested  relationship  of 
Thetironia  to  Venus,  but  in  the  absence  of  specimens  furnishing  decisive  evidence 
they  Jeft  the  former  genus  in  the  family  Veneridag.  In  its  external  form  and  thin 
shell  Thetironia  shows  some  resemblance  to  Poromya,  but  the  conspicuous  internal 
ligament  found  in  the  latter  is  alisent  in  the  former. 

In  a  systematic  list  of  Mollusca,  J.  E.  Gray  '  placed  Tkeiiroiti<i  in  the  Lucinida?, 
but  gave  no  reasons  for  assigning  it  to  that  family.  Although  elongate  markings 
do  occur  in  the  interior  of  some  species  of  Lncina,  they  show  but  little  resemblance 
to  the  angular  rib  of  TJicfironia.  Fuither,  the  hinge  is  unlike  that  typical  of  Lucina ; 
for  although  in  some  icw  species  ('■.  <j.  L.  ijiliha,  L.  pennsijloanica)  in  which  the 
mnbones  have  a  considerable  anterior  curvature,  the  positions  of  the  cardinal  teeth 
l)ecomc  somewhat  similar  to  those  in  Thetironia,  yet  this  is  clearly  a  secondary 
character  due  to  torsion  and  cannot  be  taken  as  evidence  of  any  affinity  between 
Jjucina  and  TJietironia. 

The  hinge  in  some  of  the  Corbidfe,  such  as  Sphxviola,  Gonodon,  and  Miitiella 
resembles  that  of  Thetironia,  but  is  far  stouter,  and  the  shell  is  much  thicker.  The 
hinge  in  Utricardium  also  is  somewhat  similar  to  that  of  Thetironia,  since  lateral 
teeth  are  absent,  but  the  cardinals  are  less  developed.  Unicardiiim,  however, 
differs  from  Thetironia  in  the  character  of  its  ornamentation  and  in  the  form  of 
the  shell. 

In  both  form  and  position  the  teeth  of  TJietironia  show  a  striking  resemblance 
to  the  cardinal  teeth  of  the  Cardiid;i?  (especially  to  Protocardia) ,  and  the  hinge- 
margin  in  front  of  the  umbo  expands  in  a  similar  way;  some  further  resemblance 
is  seen  in  the  position  and  prominence  of  the  external  ligament,  and  in  the  general 
form  of  the  shell,  which  is  similar  to  that  of  the  nearly  smooth  Cardium  (Serripes) 
(jramJandicum,  Chemnitz."  The  greater  development  of  ornamentation  on  the 
posterior  part  than  on  the  remainder  of  the  shell  in  Thefirovia  is  also  suggestive 
of  some  forms  of  Protocardia .  The  position  of  the  cardinal  teeth  in  the  Cardiidas 
is  practically  constant  and  is  a  character  of  systematic  importance ;  so  that  the 
close  resemblance  between  these  teeth  in  Thetironia  and  in  the  Cardiidie  seems  to 
indicate  a  real  relationship.  Opposed  to  this,  however,  is  the  absence  of  lateral 
teeth  ^  in  Thetironia ;   but  although  these  teeth  are  usually  found  in  the  Cardiida?, 

1  '  Synopsis  Brit.  Mus.,'  ed.  44  (1842),  p.  91. 

-  Although  d'Orbigny  placed  Thetironia,  in  the  Veneridae,  he  recognised  that  in  some  respects  it 
clearly  resembles  Cardium.     Sec  '  Pal.  Fran9.  Terr.  Crct.,'  vol.  iii  (184t)),  p.  4.'Jl. 

^  In  the  '  Additions  and  Corrections  '  to  his  Monograph  Stoliczka  states  that  in  Theiironia  ignohilis 
there  are  two  cardinals  and  a  minute  posterior  lateral  in  the  right  valve,  and  tliivo  cardinals  in  the 
left  valve.     '  Palieont.  Indica,  Cret.  Fauna  S.  Indica  "  (1871),  p.  48.'). 


THETIRONIA.  107 

yet  they  are  occasionally  al)sent.  Otlici*  differences  arc  seen  in  the  very  thin  and 
punctate  shell,  and  in  the  internal  ril). 

Nothing  closely  resembling  the  internal  rib  of  Thetironia  seems  to  be  known  in 
any  other  laniellibranch.  Bnt  in  some  Jurassic  and  Cretaceous  ^  species  of  Protn- 
airdia  a  rib,  either  single  or  A-shaped,  is  found  at  the  inner  Ijoundary  of  the 
posterior  area ;  this,  however,  differs  from  the  rib  of  TJidironia,  in  that  it  reaches 
the  margin  of  the  valve  and  is  not  continued  anteriorly  to  the  neighbourhood  of 
the  anterior  adductor. 

It  seems,  thei'efore,  that  although  Thetirouia  resembles  the  Cardiidic  in  several 
respects,  yet  the  points  of  difference  are  too  great  to  allow  of  its  being  included  in 
that  family. 

TiiETiiiDXiA    JiiNuu    (Suiceyhii),   1820.      Plate    XXV,    figs.    \oa—c;    Plate  XXVI, 

figs.  1—8. 

1822.     Venus,  G.  Mantell.     Foss.  S.  Downs,  p.  73. 

1826.     Thetis    minor,  /.  de   C.  Soiverhtj.     Min.  ConcL.,  vol.  vi,  p.  21,  pi.  d.viii, 

fiys.  6  (?  5). 
1829.         —  —M.J.  L.  Beftance.     Diet.  Sci.  Nat.,  v,.l.  liv,  p.  275. 

1841.         —       SowEEBii,  F.  A.  Rijmcr.     Die  Versteiii.  d.  iiord-deutscli.  Kreidugeb. 

p.  72  (jiartim). 
1845.         —  —  var.  a  minor,  var.  /3.   major.    E.  Forbes.     Quart.  Joiiru. 

Geol.  Soc,  vol.  i,  p.  242. 
184G.         —       L^viGATA,  A.  d'Orhi(jinj.     Pal.  Frauy.  Terr.  Crct.,  vol.  iii,  p.  452, 

pi.  ccclxxxvii,  figs.  1 — 3. 
1832-53.         —       MiNOE,  G.  P.  Dcshaijcs.     Traitii  Elciueut.  Conchyl.,  vol.  i,  p.  575, 

pi.  xxii,  figs.  3,  4. 
1854.         —  —J.  Morrk.     Cat.  Brit.  Foss.,  ed.  2,  p.  227. 

—  —  —       S.  P.    Woodward.     Manual  of   the  Mollusca,  fig.  221  (on 

p.  318). 

1865.        —  —F.J.  Pictet  and  G.  Cavijjkhe.     Foss.  Terr.  Crct.  Ste.  Croix 

(Mater.  Pal.  Suisse,  scr.  4), 
p.  202,  pi.  cxii,  fig.  4. 

1870.         —       LAEVIGATA,  Pick'l  uiul  Cuiiqiiche.     Iliid.,  p.  203,  pi.  cxii,  figs.  2,  3. 

—  Thetironia  minob,  F.  StoUczha.     PaliEont.  Indica,  Cret.  Fauna  S.  luilia, 

vol.  iii,  p.  158. 
1884.     Thetis  hiinok,  0.  Weertli.     Die  Fauna  des  Ncoc-oni.  iin  Teutoburg.  Walde 

(FaUvout.  Abhaudl.,  vol.  ii),  p.  41,  pi.  ix, 
figs,  5,  6. 
1898.         —       LiEViGATA,  E.    G.   Skeat  and    V.  Madsett.     Jur.  Neoc.  and   Gault 

Boidders  in  Deuiiiark, 
p.  176,  pi.  vi,  figs.  7— 9. 


•  Part  of  this  rib  is  seen  in  a  figure  given  by  Pictet  and  Cainpiche,  '  Terr.  Cret.  Ste.  Croix ' 
("Mater.  Pal.  Suisse,"  ser.  4,  18GG),  pi.  cxxi,  fig.  7a. 


168  CRETACEOUS   LAMELLIIIP.ANCHIA. 

18y5.     Thetis  minok,  F.  Vorjel.     Holliiudisch.  Kreide,  p.  58. 

I'JOO  —  —      A.  WoUemann.     Die  Biv.  u.  Gastrop.  d.  deutscb.  u.  bulliiud. 

Neocoms,  p.  118. 

Nou  1846.         —  —      A.  d'Orhi(jiiij.     Pal.  Frau?.  Terr.  Crct.,  vol.  iii,  p.  4oo,  pi. 

ceclxxxvii,  fi^'s.  4 — 7. 

—  1850.         —  —      d'Orh'ujiuj.     Prodi-,  de  Pal.,  vol.  ii,  p.  136. 

—  1868.         —  —      E.  V.  Eickwald.     Letliaea  Rossica,  vol.  ii,  p.  707,  pi.  xxvi, 

fig.  6. 

iJescrijjtiuii. — Shell  oval,  ruiinded,  convex,  slightly  (sonietimos  moderately) 
inequilatei-al ;  length  rather  greater  than  height.  Margins  forming  nearly 
regular  curves;  anterior  margin  less  convex  than  the  posterior,  making  a  ruundcd 
angle  where  it  meets  the  nearly  straight  antero-dorsal  margin.  Umbones  promi- 
nent, rather  broad,  close  together,  more  or  less  curved  forward.  Lunular  region 
depressed,  not  limited.     Postero-dorsal  region  sometimes  slightly  compressed. 

Ornamentation  consists  of  slightly-raised  concentric  lines  at  regular  intervals 
with  less  distinct  lines  between  ;  and  of  regular  rows  of  radial  pits,  whicli  on  the 
posterior  part  of  the  shell  are  replaced  by  rows  of  short  spiny  projections  or 
minute  tubercles. 

A  long,  acutely  angular  rib  extends  from  the  level  of  the  posterior  adductor 
to  near  the  umbo.  The  front  part  of  this  rib  is  continued  to  near  the  anterior 
adductor,  but  is  less  prominent  than  the  angular  part ;  at  first  it  ciu'ves  ventrally, 
and  afterwards  dorsally,  the  last  part  being  somewhat  angular. 

Measurements  .- 

(3)  (4)  (5)        (0)  (7)         (S)  (9)  (10)         (11) 

27  20-5  25  23   30  20   20  17-5  17  iiim. 
25  25   24  21-5  27  23-5  18  i&b     16     „ 

(1 — C)  Crackers,  Atlierfield. 
(7 — 11)  lutei'ual  casts,  Lower  Greeusand,  Shaukliu. 

Affinities. — Pictet  and  Campiche  separated,  but  with  considerable  hesita- 
tion, the  examples  of  Tketiroiiia  found  in  the  Crackers  of  Atliei'field  from 
those  found  in  the  Ferruginous  Rock  of  Shanklin.  The  former  they  referi'ed  to 
T.  laevigata,  d'Orbigny  (uo)i  Sowerby) ;  whilst  the  latter  are  tyi)ical  of  T.  miiuir. 
There  is,  as  stated  by  those  authors,  considerable  difficulty  in  comparing 
specimens  from  the  two  localities  owing  to  their  different  states  of  preserva- 
tion. Those  from  Atherfield  have  the  sliell  well  presei'ved  in  nearly  all 
cases,  although  not  uncommonly  the  original  form  has  been  somewhat  modified 
by  crushing.  The  specimens  from  Shaukliu,  on  the  other  hand,  are  nearly  always 
casts,  but  owing  to  the  hardness  of  the  rock  they  retain  their  original  form 
more  perfectly. 

Pictet  and  Campiche  thought   that  the  Atherfield  form  was  less  convex  and 


(1) 

(2) 

Length 

31 

30 

Height 

28-5 

29 

TllETiKO.NlA.  IG'J 

more  inequiliitcral  than  the  Shanklin  form.  After  comparing  a  considerable  number 
of  specimens  I  find  that  those  from  Atherfield  are,  as  a  rule,  slightly  less  convex ; 
but  the  more  inequilateral  character  is  not  constant ;  specimens  of  the  same  size 
are  commonly  quite  as  nearly  equilateral,  but  the  inequilateral  character  becomes 
more  marked  with  age.  Since  larger  forms  are  more  common  at  Atherfield  tlian 
at  Shanklin,  one  may  at  first  sight  get  the  impression  that  there  is  a  real  difference 
in  the  iue(juilateral  character.  I  have  not  seen  any  specimen  iVum  Atlierfield  so 
inequilateral  as  the  form  figured  by  Pictet  and  Campielie  appears  to  Ije,  and  I  tliiid< 
it  is  probable  that  their  specimen  was  somewhat  distorted  by  crushing. 

T.  geneceiisis,  Pictet  and  Roux,^  is  distinguished  from  T.  minor  by  the  heiglit  and 
length  being  equal,  b}'  its  more  nearly  equilateral  form,  and  by  a  difference  in  the 
curvature  of  the  rib  in  front  of  the  angular  part. 

BemarliS. — Thetlronia  has  been  recorded  by  I'hillips  and  .ludd  fi'oni  the 
Speeton  Clay,  ])ut  I  have  not  seen  any  examples  from  tliat  deposit.  In  some 
collections  from  Speeton  specimens  of  Gijprlnci  have  been  identified  as  Tlictironia. 

Type. — Fig.  6,  Lower  Greensand  of  Shanklin ;  in  the  British  Mu.seum.  The 
original  of  fig.  5  from  near  Lj'me  Regis  has  not  been  seen. 

Distribution. — Lower  Greensand:  Crackers  of  Atherfield;  also  recorded  l)y 
Fitton  from  the  Per;/ (t-bed  and  Beds  vi,  viii,  ix,  x,  xiii,  and  xiv  l)et\veen  Ather- 
field and  Blackgang  Chine.  Ferruginous  Sands  of  Sliaidvlin.  Atlierfield  Beds  of 
East  Shalford.  Hythe  Beds  of  Hythe.  Sandgate  Beds  of  Sandgate,  etc.  Folke- 
stone Beds  of  Folkestone. 


Theiikonia  l.kvi.;.vt.v  {Sna-n-}„i),  1818.     Phite  XXVI,  figs.  9—1-1. 

1818.      CoRiiULA  L.EViGATA,   /.   Soicvrhi/.       Mill.    CoUC'll.,    vul.   ill,    1'.    1  I.   [il.   CL'ix, 

figs.  1,  2. 
182G.     Thetis  major,  /.  de  C.  Suirerhij.     Ibid.,  vol.  vi,  p.  20,  pi.  dxiii,  fif,'s.  1 — I. 
1829.         —  ~       M.J.  L.  Di/raiice.     Diet.  Sci.  Nat.,  vol.  liv,  p.  27G. 

1850.     Unicaedium  ljevigatum,  A.  d'Orhignij.     Prodr.  de  Pal.,  vol.  ii,  p.  1(33. 
1854.     Thetis  l.*:vigata,  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  227. 
—  —       MAJOR,  Afurris.     Ibid.,  cd.  2,  p.  227. 

18(52.         —  —       J.  a.  Cluiiii.     Mauuel  de  Coiichyl.,  vol.  ii,  p.  90,  fig.  405. 

18G5.         —  —       F.J.  Fictetaiul  G.  Citiiijilche.     Foss.  Terr.  Cret.  St  t-.  Croi.\ 

(Mater.  Pal.  Suisse,  ser.  4),  pp.  209, 
210,  pi.  cxii,  fig.  5. 


1  Pictet  aiid  Rous,  '  Moll.  Foss.  Grc-s  verts  de  Geucve'  (1852),  p.  420,  pi.  xxx,  fig.  2.  Pictet  and 
Campicbe,  '  Terr.  Cret.  de  Ste.  Croix  '  (18(55;,  p.  20(5,  pi.  cxii,  tig.  7.  Barrois  records  T.  (jciicvensis  from 
the  Upper  Greeusaud  of  Lulwortb,  but  I  have  iiot  seen  any  specimens  ;  see  Barrois,  '  Terr.  Cret.  Sujht. 
de  I'Angleterre,'  etc.  (187G),  p.  90. 


170  CRETACEOUS   LAMELLIBRANCHIA. 

?  18U8.     TuETis  MAJuit,  .1.  Briarl  and  F.  L.  Curnel.     Muulu  de  l>rac<|uei,'uii.'i5  (Mi'in. 

cour.  et  Mt'ui.  des  Sav.  L'traugers,  vol. 
xxxiv),  p.  83,  pi.  vii,  figs.  14,  15. 
1871.     FiJiuiuELLA  LJiviGATA,    F.    Stol icxJcti.      Palicout.    Iiidica,   Cret.    Fauua  S. 

ludia,  Vol.  iii,  p.  24G. 
1882.     Thetis  majob,  P.  de  Loriol.     Gault  de  Cosue,  p.  (Jl,  {A.  viii,  figs.  6 — 8. 
rl874.         —  —       W.  Daiiu'g.     Zeitschr.  d.  deutsdi.  geol.  Gesellscb.,  vol    xxvi, 

p.  7(3(3,  pi.  xxi,  fig.  4. 
1885.         —  —       F.  Nutlinij.     Die  Fauna   d.    baltiscli.    Ceuomau.  (Palscout. 

Abliaudl.,  vol.  ii),  p.  2'J,  pi.  v,  fig.  (3. 

Non  1845.         —       Sowerbii  var.  li  majuk,  E.  Furbcs.     Quart.  Joiu-u.  Geol.  Soc,  vol.  i, 

p.  242. 

—  1846.         —       majok,  ^1.  d'Orhlijiiy.     Pal.  Frauc,'.  Terr.  Cn't.,  vol.  iii,  p.  454,  vol. 

ccclxxxvii,  figs.  8 — 10. 

—  —  —       LasviGATA,  d'Orbiijni/.     Ibid.,  vol.  iii,  p.  452,  pi.  ccclxxxvii,  figs.  1 — 3. 

—  1850.         —  —         d'Orblymj.     Prodr.  de  Pal,  vol.  ii,  p.  118. 

—  —  —       MAJOR,  d'Orhhjnij.     Ibid.,  vol.  ii,  p.  160. 

V —  1852.         —       SowERBYi,  ii'.  JiHtr.    Deuksclir.  d.  k.  Akad.  Wissenscli.  Wieii,  Math.- 

uat.  CI.,  vol.  iii,  p.  311,  pi.  xvi,  fig.  21. 
'i  —  1868.         —       MAJOK,  E.  V.  Eichwald.     Letha;a  Kossica,  vol.  ii,  p.  708. 

Mi'iisiircmciitft  : 

(1)        (L-)        (:!)        (.1.)  (5)  ((!) 

Length     .     47     -1-2     -11     o9     30-5     29-5 
Ht'iglit      .     43     40     39     37     27        28 

(1—10  Blackdowu. 

Ajjinitirs. — This  species  is  closely  allied  to  1\  minor,  with  which  it  was  uiiitcil 
liy  ll(")iiiei-  under  the  name  T.  Soiccrlni,  but  it  possesses  relatively  higher  and 
narrower  uniljones  than  T.  minor.  T.  laivijata  is  commonly  of  larger  size  than 
T.  mJiKir,  and  as  in  the  case  of  the  latter,  the  large  forms  are  more  inequilateral 
than  the  small  I'urms.  A  ratlier  small  example  was  figured  by  Sowerby  as  ('orlmhi 
Iciivvjiilii,  ami  Avas  taken  l)y  Stoliczka  as  the  type  of  a  new  genus  Fimbriella,  but  it 
pi'oves  to  be,  as  was  suggested  by  Pictet  and  Cam])iche,  an  example  of  1\  viajur. 

The  hinge  can  be  seen  in  some  specimens  from  Blackdown  (Plate  XXVI,  figs. 
19  A,  14).  It  consists  of  two  small  conical  or  tubercular  teeth  just  below  the 
umbo  of  each  valve.  In  the  right  valve  the  teeth  are  placed  one  above  the  other, 
but  the  dorsal  tooth  is  slightly  in  front  uF  the  ventral  and  rather  smaller  than  the 
latter.  In  the  left  valve  the  teetli  are  side  by  side,  nearly  on  the  same  level, 
and  the  anterior  tooth  is  rather  larger  than  the  posterior.  Lateral  teeth  are 
absent.     The  external  ligament  is  short  and  prominent. 

Ti/pes. — The  type  of  ('orhula  ln'chjata,  from  Blackdown,  and  the  types  of 
Thetis  major,  from  Blackdown  and  Devizes,  are  in  the  British  Museum.  T.  major 
is  the  type  of  the  genus  Thetis,  tSowerb}-. 


(7) 

(S) 

(■J) 

22-5 

22 

13  mm. 

21 

22 

13     „ 

TELLINA.  171 

Distrihiifioii.—GAv\\t  of  Black  Ven.     Upper  Greensand  (zone  of  Schlocnhachia 

rostrata)  of  Blackdown,  Potternc,  Devizes,  and  near  Lyme  Hegis.  Recorded  by 
Price  from  tlie  Gault  of  Folkestone. 


i^.n/;////— TELLINIDyE,  Dcshai/rp. 
Genus — Tellina,  TAnnxu^. 

(•Syst.  Nat,,'  eel.  10,  1758,  p.  C74 ;  e.l.  12.  1707,  p.  lUG.) 

Teli.ix.v  Carteront,  ,rOrhhnui,  1S45.     Plate  XXVI,  figs.  1-"),  IG. 

1842.     Tellina  ?  vel  Psammobia  ?  angulata,  Deshayes  in  A.  Leymerie.    Mem.  Soc. 

geol.  de  Prance,  vol.  v,  pp.  3,  24, 
pi.  iii,  fig.  6  (uon  T.  amjulata,  L.). 
1845.  —        ANGULATA  ?,  E.  Forhes.     Quart.  Journ.  Geol.  Soc,  vol.  i,  p.  239. 

—        Tellina  Carteroni,  A.  d'Orhiijmj.     Pal.  Franc.  Terr.  Crcl.,  vol.  iii,  p.  420, 

pi.  ccclxxx,  figs.  1,  2. 
1850.  —  —  (VOrhujny.     Prodr.  de  Pal.,  vol.  ii,  p.  75. 

18(31.  —  —  p.  (7e  Loriol.     Anini.  Invert.  Foss.  Mt.  Salcve,  p.  5i), 

pi.  vii,  fig.  2. 
1865.  —  —F.J.  Field  and  G.  Campiche.     Foss.  Terr.  CrJt.  Ste. 

Croix  (Mater.  Pal.  Suisse,  ser. 
4),  p.  134. 
1870.  —  —  F.  StoUrxlca.     Palocout.  ludiea,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  123. 
1884.  —  —         0.  Weertli.     Die  Fauna  des  Neocom.  im  Teutoburg. 

Walde   (Pala;ont.  Abhandl.,  vol.  ii), 
p.  41. 
1895.  —  —  Cf,  Maas.     Zcitsclir.  d.  deutscli.  gool.  Gesellsch.,  vol. 

xlvii,  p.  257. 
1900.  —  —  A.  Wollcmann.     Die  Biv.  u.  Gastrop.  d.  doutsch.  n. 

lioUiind.  Neoconis,  p.  121. 

Descriplion. — Shell  elongate,  much  compressed,  inequilateral,  length  equal  to 
more  than  twice  the  height.  Anterior  margin  rounded,  curving  rapidly  to  join 
the  slightly  curved  ventral  margin.  Posterior  margin  oblique,  forming  an  angle 
with  the  ventral  margin,  A  shallow  furrow  passes  from  the  umbo  to  the  middle 
of  the  ventral  margin.  ITmbones  small,  curved  forward.  A  .sharp  carina  extends 
in  a  curve  from  the  umbo  to  the  postero-ventral  angle,  and  cuts  off  a  narrow, 
flattened,  postero-doi'sal  area.  Ornamentation  con.sists  of  fine  radial  ribs  on  the 
anterior  and  ])o.<:terior  parts  of  the  valves,  especially  just  in  front  of  the  carina  ; 
growth-lines  distinct. 


172  CRETACEOUS  LAMELLTBRANCHIA. 

Measurements  : 

(1)  (2)  (3)  (1) 

Length         39-2         .  39         .         38         .         30    mm. 

Height         17  .  10         .         10-5      .         15-2    ., 


"D 


(1 — 4)  Crackers,  Atherfield. 


Affinities. — The  English  specimens  differ  from  the  figure  of  T.  Carteroni  given 
l)y  d'Orbigny  in  the  greater  curvature  of  the  carina,  the  narrower  postero-dorsal 
area,  and  the  greater  upward  bend  of  the  anterior  end  of  the  shell.  Professor 
T3oule  has  kindl}-  examined  the  specimen  figured  by  d'Orbigny,  and  states  that 
the  carina  is  more  curved  and  the  postero-dorsal  area  narrower  than  represented 
in  the  figure ;  also  the  anterior  part  has  been  restored.  Professor  Boule  has  also 
compared  a  photograph  of  a  specimen  fi-om  Atherfield  with  d'Orbignj^'s  specimen 
and  considers  that  they  do  not  differ  specifically.  Pictet  and  Campiche  w'ere  able 
to  compare  English  with  French  specimens,  and  the  principal  difference  which  they 
noted  was  the  occurrence  of  fine  radial  ribs  on  the  ]iosterior  part  of  the  shell  in 
English  specimens;  but  I  find  that  those  ribs  are  indistinct  or  absent  in  specimens 
which  are  not  quite  perfectly  preserved. 

The  figure  of  T.  angnlata  given  by  Deshayes  appears  to  differ  from  7'.  ('iirtryinii 
in  its  more  elongate  form  and  the  greater  length  of  the  anterior  region,  but  these 
differences  are  probal:)l3'  due  to  the  imperfection  of  the  specimen.  Previous  writers 
have  not  regarded  it  as  distinct  from  d'Orbigny's  T.  Garteroni. 

Stoliczka  regarded  T.  Garteroni  as  a  typical  Tellina.  It  resembles  closely  the 
sub-genus  Phijllodn,  Schumacher. 

One  specimen  fi'om  Atherfield  (Plate  XXVI,  fig.  17)  differs  from  the  other 
examples  of  this  species  in  the  occurrence  of  strong  radial  ril)s  on  the  posterior 
part  of  the  shell.     It  may  be  only  a  variety  of  T.  Garteroni. 

Tij2)e. — From  the  Neocomian  of  Vendeuvre  ;  the  original  cannot  be  found.  The 
specimen  figured  by  d'Orbigny  came  from  Marolles. 

Distribution. — Lower  Greensand  (Crackers)  of  Atherfield.  Atherfield  Beds 
of  East  Shalford. 


TEf.r.iXA  sTR r ATI- 1.01  m-.s,  Stolirzht,  1870.      Plato  XXVI,  figs.  18,  19;  Plate  XXVII, 

fig.  1 . 

1824.     Tellina  stuiatula,  J.  de  C.  Sowerhy.     Min.  Condi.,  vol.  v,  p.  70,  jil.  cccclvi, 

fig.  1  (iKiu  T.  atriiitidd.  Olivi, 
Pxiltoii,  Lainarck). 

1850.  —  —A.  d'Orhlij,,;/.     rrodr.  di-  Pal,  vol.  ii,  p.  l.W. 

1854.  —  —  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  226. 


TELLINA.  173 

1865.     Tkllina  stuiatula,  F.  J.  Pictet  and  G.  Campiche.     Poss.  Terr.  Crct.  Ste. 

Croix  (Miiti'r.  Pal.  Suisse,  ser. 
4),  p.  IS'J. 
1870.  —         (TELLiNELhA)  sTRiATVLOiDES,  F.Stoliczka.   Palaeout.  Indica,  Cret. 

Fauna  S.  India,  vol. 
iii,  p.  123. 

Descrijjfion.^tiheW  elongate-oval,  compressed,  inequilateral;  length  equal  to 
about  twice  the  height ;  the  anterior  part  longer  than  the  posterior  part.  Anterior 
margin  rounded.  Ventral  margin  slightly  curved,  making  an  angle  with  the 
posterior  mai'gin.  Posterior  margin  oblique,  curved  near  the  postero- ventral 
angle,  and  forming  an  obtuse  angle  with  the  postero-dorsal  margin.  Unibones 
inconspicuous,  only  slightly  curved.  A  rounded  carina  extends  in  a  nearly  straight 
line  from  the  umbo  to  the  postero-vcntral  angle,  and  cuts  off  a  flattened  postero- 
dorsal  area.  Ornamentation  consists  of  small  radial  ribs  on  the  postero-dorsal  area 
and  ou  the  part  just  in  front  of  the  carina ;  also  on  a  small  part  of  the  shell  near 
the  anterior  margin.  Fine  concentric  lines  are  also  present,  and  are  more 
distinct  on  the  anterior  and  posterior  parts  of  the  shell  than  elsewhere.  Pallial 
sinus  relatively  small,  somewhat  angular. 

Measurements  : 

(1)  (2) 

Length         .         30         .         27  Jum. 
Height         .        14-6        .        13-2   „ 

(1—2)  Blackdowu. 

Affinities. — Stoliczka  placed  this  species  in  the  sub-genus  Tellinellu,  witli  which 
it  agrees  closely  in  external  form,  but  the  ol)li(pie  cardinal  teeth  resemble  more 
closely  these  of  the  sub-genus  I'aliwvurra. 

Tijije. — From  Blackdowu ;  in  the  British  Museum. 

Bistrihutiun. — Upper  Greensand  (zone  of  Schlanihachia  rostrata)  of  Blackduwu 
and  Haldon.  Recorded  by  Jukes-Browne  from  the  higher  part  of  the  zone  of 
Pecten  aspcr  in  North  Dorset. 


Section — P.\l.eomu;i{a,  F.  Stoliczka,  1870. 

('Palaeont.  ludica,  Cret.  Fauna  S.  India,'  vol.  iii,  p.  IIC.) 

Tellina  (PALjiOM(ERA)  iN/EQUALis,  Soiverbij,  1824.     Plate  XXVII,  figs.  2—8. 

1824..     Tellina   in.kqualis,  J.  de  C.  Sowerhij.     Min.  Conch.,  vol.  v.  |).  80.  pi. 

ccc-clvi,  fij^.  2. 
1850.     Aecopaoia       —  A.d'Orbigny.     Prodr.  de  Pal,  vol.  ii,  p.  158  (^»ar/im). 

1854.     Tellina  —  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  226. 

23 


\7l  CRETACEOUS   LAMELLIBRANCIIIA. 

y  IStJy.     Tellina    iNj;<iUA.Lis,  A.  Biiaii  and  F.  L.  Conwt.     Mculu  de  lii-acqufguies 

(Miin.  cour.  et  Mc'iii.  des  Sav. 
ctrangers,  vol.  xxxiv),  j).  77,  pi. 
viii,  figs.  24,  25. 
1870.     Abcoi'agia       —  (Lineaeia),   F.    Stoliczka.     Palaeont.    ludica,   Cret. 

Fauna  S.  India,  vol. 
iii,  p.  124. 
Nou  lb4.5.     Tellina  —  't',  E.  Forbes.    Quart.  Jouru.  Geol.  Soc,  vol.  i,  p.  2'3'J. 

Descrqifiov. — Shell  oval,  moderately  inequilateral ;  length  rather  more  than 
1^  times  thf  height;  left  valve  less  convex  than  the  right.  Anterior  part  of 
valve.s  rounded.  Posterior  margin  convex,  subtruncate,  more  or  less  ob]i(|ue, 
forming  a  blunt  angle  with  the  ventral  margin.  A  slight  carina  extends  from  the 
umbo  to  the  postero-ventral  angle  and  cuts  off  a  flattened  postero-dorsal  area. 
Umbones  moderately  prominent.  I'allial  sinus  large,  rounded.  Postero-dorsal 
area  ornamented  with  small  radial  ribs;  the  remainder  of  the  shell  smooth 
except  for  growth-lines. 


Measurements  : 

(1) 

(2) 

(3) 

(i) 

(5) 

(0) 

Length 

29     . 

28     . 

27 

.  2G       . 

23-5     , 

.      18  mm 

Height 

18-5    . 

18     . 

17 

.   16-5    . 

14-5 

.      11     „ 

Thickness    . 

9      . 

7-5. 

8 

.     7-25 . 

()-5 

?J 

(1—6)  BlaekdoAvii. 

Aj]iiiiti<'H. —  T.  slriijata  Goldfuss,^  from  the  Aachen  Greensand,  is  simihir  in 
form  to  T.  iiueijunlix,  but  possesses  fine  radial  ornamentation  over  the  entire  surface 
of  the  shell.  T.  liui/imti,  d'Orbigny,-  is  also  similar  in  form,  but  appears  to  be  more 
nearly  ecpiilateral  and  without  radial  ribs. 

A  species  of  TcUimt  found  in  the  ]\leule  de  Hracquegnies  was  referred  to 
T.  iiueqiniJis  by  Briart  and  Cornet,  but  it  appears  to  differ  in  some  respects  fi'om 
the  latter.  The  specimens  which  I  have  seen  from  Bracquegnies  are  not 
sufficiently  well  preserved  to  enable  me  to  express  a  defiuito  opinion  as  to  their 
relationship  to  T.  insequalis. 

Ti/pc—Vvoni  the  Upper  Greensand  of  IJlackdou  n  ;  in  the  British  Museum. 

Distrlbnliua. — Upper  Greensand  (zone  of  SchlanbacJiin  nislniln)  of  Blackdown 
and  Ilaldon.  Recorded  by  Jukes-Browne  from  the  Upper  Greensand  of  Devizes 
and  the  Isle  of  Wio-ht. 


'O' 


'  '  Petrel'.  Genu.,' vol.  ii  (1840),  p.  234,  pi.  cxlvii,  ii^-.  18.  Holzapi'el,  'Die  MoUusk.  Aachen. 
Kreide '  (PaloGoutograpliica,  vol.  xxxv,  1889),  p.  159,  pi.  xi,  figs.  G-10.  Tliis  species  is  the  type  i^ii'  the 
sub-geuus  or  section  Puhvmcera,  Stolie/.ka,  1870. 

2  'Pal.  Frauy.  Terr.  CrJt.,'  vol.  iii  (1845),  p.  422,  pi.  lclI.x.x-x,  tigs.  0-11. 


TELLINA.  ]  75 


Svh-f}eiiv.<i — LiNEAKiA,  T.  A.  Covrad,  18G0. 

('  Jouni.  Acad.  Nat.  Sci.  PliiLnl.,'  scr.  2,  vol.  iv,  p.  270,  ami  '  Amer.  Joiirn.  Conch.,'  vol.  vi 

[1870],  p.  73.) 

Ti.;tj,i\a  (Lineatjia),  sp.     Plate  XXVII,  fig.  9. 

J)escriptioii. — Shell  oval,  moderately  convex  witli  tiattcned  sides,  nearly 
equilateral.  Anterior  margin  ronnded.  Ventral  margin  slightly  convex.  Posterior 
margin  slightly  truncated,  rounded.  Umbones  inconspicuous.  Postero-dorsal 
region  slightly  compressed,  but  not  limited  by  a  carina. 

Ornamentation  consists  of  numerous,  strong,  regular,  concentric  rilis  separated 
by  narrow  grooves  ;  and  a  few  small  radial  ribs  on  the  anterior  and  posterior 
parts,  those  on  the  latter  sometimes  not  reaching  the  margin.  Length  lG"o  mm.; 
height  10-5  mm. 

Affinities. — This  species,  of  which  only  a  few  examples  have  been  seen,  is 
closely  allied  to,  if  not  identical  with,  T.  Baulinimia  (d'Orbigny),^  but  the  posterior 
ribs  are  less  prominent.  The  shell  is  less  elongate  than  is  d'Orbigny's  type,  Ijut 
scarcely  differs  in  this  respect  from  the  example  figured  by  Pictet  and  Campiche.  It 
is  more  elongate  and  has  the  postero-dorsal  region  less  flattened  than  in 
T.  ftubconcentricn  (d'Orbigny)."     T.  ftuhhrrcijvira,  Maas,  is  another  similar  form. 

Distribution. — Lower  Greensand  (Crackers)  of  Atherfield.  Atherfield  Beds  of 
East  Shalford.^ 


Tkt.uxa  (Lixearta)  .sudtenuistkiata,  iVOrhiijny,  1850.     Plate  XXVII,  figs.  10 — 13. 

1836.     Amphidesma  ?  tenttistriatum,  /.  (h  C.  Sowerhy.     Trans.  Geol.  Soc.,  ser.  2, 

vol.  iv,  pp.  230,  341, 
pi.  xvi,  fig.  7. 
1850.     Teli.ina  subtenuistriata,  A.  iVOrhigiiy.     Prorlr.  dc  Pal.,  vol.  ii,  p.  150 

(nou  T.tennisiriata,  Desliayes, 
1824). 
1854.     Amphidesma  ?  tenuisteiatum,  J.  Morris.     Cat.  Brit.  Foss.,  cd.  2,  p.  183. 


1  For  references  see  p.  176,  footnotes  1  and  2. 

-  Some  specimens  from  the  Folkestone  Beds  of  Folkestone  agree  in  form  witli  T.  xvhconcenlrica, 
hut  owin<i  to  the  imperfect  preservation  of  the  surface  the  character  of  the  ornamentation  cannot  be 
made  out  satisfactorily. 

3  It  is  possible  that  TeUina  xqunlig,  Mantell  {iiom.  nu(l.),  from  the  Lower  Greensand  of  rarham, 
mav  1)1'  the  form  described  above.     Mantell,  '  Tran.-;.  Geol.  Soc..'  ser.  2,  vol.  iii  (1820),  p.  211. 


17G  CRETACEOUS   J.AMELLIBRANCHIA. 

1865.     Tellina  subtenuistriata,  F.  J.  Pidcl  and  G.  Campiche.     Foss.  Terr.  Crit. 

Ste.   Croix    (Mater.    Pal. 
Suisse,    ser.  4),   pp.  132, 
138. 
1870.     Amphidesma  tenuistbiatum,  F.  Stoliczka.     Palaeont.  InJica,  Cret.  Fauna 

S.    India,    vol.    iii,   p.    Ill 
{?Thracia  or  Tellina). 

Description. — Shell  oval,  of  moderate  convexity,  nearly  equilateral.  Anterior 
margin  rounded ;  ventral  margin  moderately  convex ;  posterior  margin  truncated, 
more  or  less  oblique,  forming  a  blunt  angle  with  the  ventral  margin,  and  an  obtuse 
angle  with  the  postero-dorsal  margin.  Umbones  rather  liroad,  scarcely  curved. 
Postero-dorsal  part  of  shell  compressed  and  flattened. 

Ornamentation  consists  of  numerous  strong,  regular,  concentric  ribs,  and  of  a 
few  small  radial  ril)s  on  the  anterior  pai-t,  and  of  a  larger  number  on  the  postero- 
dorsal  region  and  the  part  just  in  front  of  it. 

Measurements  : 

(1)  (2)  (3)  (1) 

Length         .  19         .  18         .         17         .  1:5  nun. 

Height         .         13-5      .         13         .         11-5      .  9     „ 

(1 — 4)  Blackdown. 

AlJiiiities. — This  species  resembles  Tellina  Ihmllniana  (d'Orbigny),'  but  possesses 
a  relatively  shorter  and  liigher  shell,  with  a  more  convex  ventral  margin  and  more 
numerous  radial  ribs.  In  form  it  approaches  more  nearly  the  examples  from  the 
Gault  of  the  Pertc  du  Rhone  figm^ed  by  Pictet  and  Campiche,-  but  in  the  latter 
the  posterior  extremity  is  more  angular  and  the  posterior  riljs  more  prominent  and 
limited  to  the  postero-dorsal  region. 

T.  subtenuistriata  also  resembles  T.  subconcentrica  (d'Orbigny),^  l)ut  is  more 
nearly  equilateral  and  the  ventral  border  is  more  convex. 

It  differs  from  the  species  from  the  Lower  Greensand  described  above  in  the 
flattened  postero-dorsal  region,  the  more  angular  posterior  extremity,  the  smaller 
a[)ical  angle,  the  larger  curvature  of  the  ventral  margin,  and  greater  relative 
height.     1\  siibhercynica,  Maas,*  is  another  similar  form. 

Bemarhs. — The  type  is  somewhat  imperfectly  preserved,  but  the  radial  ribs  on 
the  anterior  and  posterior  parts,  which  are  not  shown  in  Sowerby's  figure,  can  be 
made  out  satisfactorily.  The  size  of  the  apical  angle  and  the  outline  of  the  shell 
vary  in  different  examples. 

1  '  Pal.  Franv.  Terr.  Crct.,'  vol.  iii  (1845),  p.  411,  pi.  ccckxviii,  figs.  7-10. 
-  Pictet  and  Campiche,  '  Terr.  Cret.  Ste.  Croix '  (1865),  p.  141,  pi.  cix,  figs.  1-3. 
■'  Op.  cit.,  p.  410,  pi.  ccclxxviii,  figs.  1-C,  and  '  Prodr.  de  Pal.,'  vol.  iii  (1850),  p.  75.     Pictet  and 
Renevier,  '  Foss.  Terr.  Aptien'  (Mati'r.  Pal.  Suisse,  ser.  1,  1856),  p.  69,  pi.  vii,  fig.  7. 
'  'Zeitschr.  dcr  deutscb.  geol.  Gesellscli.,'  vol.  xlvii  (1895),  p.  258,  pi.  vi,  figs.  3,  4. 


MACTRA.  177 

Type. — From  Blackdown ;  in  tlie  Bristol  Museuin. 

Distribution. — Upper  Greensand  (zone  of  Schlamhachia  rostrata)  of  Blackdown. 

Tellina  (Lineaeia)  sp.     Plate  XXVII,  figs.  14— IG. 

Beseription. — Shell  oval,  moderately  convex,  with  flattened  sides,  nearly  equi- 
lateral. Anterior  and  posterior  margins  rounded.  Ventral  margin  only  slightly 
curved,  and  nearly  parallel  with  the  dorsal  margin.  Umbones  broad,  nearly  median. 
Postero-dorsal  part  of  valve  flattened,  rather  large,  limited  by  a  faint  carina. 

Ornamentation  consists  of  numerous  small,  regular,  concentric  ribs,  and 
numerous  small  radial  ribs  on  the  postero-dorsal  area  and  near  the  anterior  end. 

Measurements  : 

(1)  (2)  (3) 

Length  17         .  15         .         14     mm. 

Height         .         12         .         10         .  9-5     „ 

(1—3)  Blackdown. 
Affinities. — This  species  resembles    T.  BauUniana  (d'Orbigny),  Ijut  tlie  radi:il 
ribs  are  much  more  numerous.     It  is  also  similar  to  the    form    from  the    Lower 
Greensand  described  above,  and  to  T.  .•<iil>h<')ri/iiica,'Maas. 

Distrihnfinu. — Upper  Greensand  (zone  of  Schlcenbachia  rostrata)  of  Blackdown. 


i^aJHi/y— MACTRID^,  Clra>/. 

Genus — Mactra,  Linnseus,  1 7Cu. 
('  Syst.  Nat.,'  ed.  12,  vol.  i,  p.  1125.) 

Mactba,  sp.     Plate  XXVII,  figs.  17,  18. 

A  few  specimens  which  rescml)le  Mnctra  extcrnallv,  but  of  which  the  hinge  has 
not  been  seen,  were  found  in  the  Lower  Greensand  (Ferruginous  Sands)  of  Shank- 
lin  by  the  late  C.  J.  A.  Meyer.  They  are  rather  larger  and  relatively  higher  than 
M.  (UKjulatti,  and  the  carina  is  less  distinct.  The  surface  of  the  shell  is  ornamented 
with  small  concentric  ribs. 

Mactra  angulata,  Sowerhy,  1830.     Plate  XXVII,  figs.  19—23. 

1836.     Mactea  ?  ANGULATA,  J.  dc  C.  Sowerhy.     Tran.s.  Gcol.  Soc,  ser.  2,  vol.  iv. 

]>]>.  241,  341.  pi.  xvi,  fig.  9. 
1850.     Mactea  anoulat*,  A.  (VOrhi(ji)y.     Prodr.  do  Pal.,  vol.  ii,  p.  158. 


178  CRETACEOUS   LAMELLIBRANCHIA. 

1854.     Mactra  anoulata,  /.  Morris.     Cat.  Brit.  Foss.,  eil.  2,  p.  2U9. 

18(35.  —  —         F.  J.  Bidet  and  G.  Campiche.     Foss.  Terr.   Crut.   Ste. 

Croix    (Mater.    Pal. 

Suisse,  sor.  4),  p.  120. 
1870.  —  —         F.  StoUczka.     Falseont.  Imlica,  Cret.  Fauna  S.  ludia, 

vol.  iii,  pp.  55,  56. 

Non  1851.  —  —         J.  MiiUi'r.     Petref.  dcr  Aaclien.  Kreidef.,  pt.  2,  p.  66 

(=  M".  Bosquetiana,  Stoliezka). 

—     lOOl.  —  —         F.  Sturm.     Jaliili.  <1.  k.  prcuss.  fjeol.  Landesanst.  fiir. 

r.»L)U,  vol.  xxi,  p.  84,  pi.  viii,  fit;.  1. 

Description. — Shell  small,  convex,  Rul)triangiilar,  slightly  incquilatoral,  with 
the  antero-  and  |)ostero-dorsal  parts  bending  raj)idly  to  the  margins.  Antero- 
dorsal  margin  long.  Anterior  margin  ronnded.  Ventral  margin  convex,  forming 
an  angle  with  the  posterior  margin,  which  is  trnncated,  oblique,  and  slightly  convex. 
Umbones  prominent,  pointed,  curved  inwards,  with  a  carina  which  extends  in  a 
gentle  curve  to  the  postero-ventral  angle.  Ornamentation  consists  of  fine  con- 
centric ribs,  wliifli  l)i'coni('  fewer  and  stronger  near  llie  antero-(loi-s;d  and  posfcro- 


dorsal  marcfin. 

Mpdsurcmpufii : 

(1) 

Length 

14 

Height 

12 

(2)  (3)  (4) 

13         .  10         .         8  mm. 

10-5      .         8  .         7     „ 

(1 — 4)  Blackdovm. 

Affinities. — In  form  and  ornamentation  M.  nuijiilKfn  resembles  M.  Warrrnana, 
Meek  and  llayden,^  but  the  latter  is  of  larger  size  and  the  umbones  show  a  distinct 
anterior  curvature. 

A  species  found  in  the  Aachen  Grecnsand,  now  known  as  if.  Bosquetiana, 
Stoliezka,  was  identified  with  M.  nnr/nJata  by  Midler,  but  is  distinguished  from 
I  he  latter,  as  Stoliezka  pointed  out,  by  its  greater  length,  smaller  convexity,  rotinded 
posterior  margin,  and  other  characters. 

Ti/jje. — From  Blackdown  ;  in  the  Bristol  Museum. 

l^istrihntion. — Upper  Greensand  (zone  of  Selihvnhachia  rostra t a)  of  Blackdown 
and  Ilaldon.  Recorded  by  Barrois  from  the  Upper  Greensand  of  Tjulworth  and 
by  Jidces-Brownc  from  the  equivalent  of  the  Blackdown  Beds  at  Sidmouth. 

1  Meek,  'Invert.  Cret.  and  Tort.  Foss.  U.  Missouri '  (187(i).  P-  208,  pi.  xxx,  fig.  7.  Wliiteaves, 
'  Mesozoic  Foss.'  (aeol.  Surv.  Canada),  vol.  i  (187;>),  p.  142,  pi.  xvii,  fig.  9,  pi.  xix.  fig.  3. 


[■TVL'liUMVA.  I7<j 


iJciuLH — Ptvuiidmva,  L.  Jfjii.sai::,  JSL'J. 
(•  Etudos  crit.  Mull,  i'oss.' ;  Mjus,  p.  xviii,  pi.  .vi,  ligs.  ;),  1-.) 

Ptychomya   Rouix.vi,iii\A   {irOrblijuij),  18-^1.1-.      i'late  XXVII,  figs.  24—20. 

1842-45.     Ptychomya  plana,  L.  Ajtcy^iz.     J'Jtuilos  crit.   Moll.   Foss. ;    Myes,  p.    xviii 

(1845),  pi.  xi,  fii,'s.  3,  4  (1842). 

1844.  Ckassatella  kuuinaluina,  ^1.  tVOrbiijinj.     Tal.  Frau^.  Terr.  Crt't.,  vol.  iii, 

p.  75,  pi.  cclxiv,  figs.  10 — 13. 

1845.  —  —  E.   Foi-hi-s.     Quart.  Jouni.  Geol.   Soc,  vol.  i, 

p.  241. 
1850.  —  —  d'OrhifjMj.     Prodr.  de  Pal.,  vol.  ii,  p.  77. 

1854.  —  —  /.  MurrU.     Cat.  Brit.  Fuss.,  ed.  2,  p.  19(3. 

1855.  —  —  G.  Cotlcaii.     Mull.  Fuss,  de  I'Youue,  p.  71. 
180(J.     Ptychomya                —              F.  J.  Fidel  and  (V.  Cainpichc.  Foss.  TeiT.  Crt't. 

Ste.  Croix  (MatiT.  Pal.  Suisse, 
ser.    4),    p.    352,    pi.    cxxvii, 
figs.  2— (i. 
18(J9.     IvAUlocoNCHA  —  T.  A.   Conrad.     Aiiier.   Juuru.    Couch.,    vol.   v, 

p.  47. 

Dr>icrq)lioii. — SliL'll  uval-o!)luiiii-,  fluiigate,  convex,  but  with  Hattoucd  sides,  very 
iue(|iiilaterul,  anterior  part  rather  higher  than  the  posterior  part.  Anterior 
margin  regularly  rounded.  Ventral  margin  oidy  slightly  curved,  nearly  parallel 
to  the  dorsal  margin.  Posterior  margin  oblique,  forming  an  acute  angle  w  ilh  the 
ventral  margin  and  an  obtuse  angle  with  the  slightly  curved  postero-dorsal  margin. 
Umboues  inconspicuous.  On  the  postero-dorsal  sitle  of  a  line  from  the  umbone  to 
the  posterior  extremity  the  shell  is  flattened.     Lunule  narrow,  elongate. 

Ornameutatiou  consists  of  strong  radial  ril)s,  which  are  .sometimes  more  or  less 
nodose.  Those  on  the  pu.sterior  part  uf  the  shell  are  stronger  and  separated  by 
broader  furrows  than  those  on  the  anterior  part.  The  ribs  which  reach  the 
posterior  margin  start  from  the  timbo ;  the  others  start  from  a  line  between  the 
umbo  and  a  point  on  the  opposite  margin  which  is  about  a  quarter  of  the  distance 
from  the  anterior  to  the  posterior  end.  In  front  of  this  line  the  ribs  form  a 
considerable  curve ;  behind  it  they  are  only  slightly  curved;  the  ribs  meet  at  an 
acute  angle  at  the  line  mentioned  Forming  either  a  A  throughout  or  a  chevron  M, 
on  the  ventral  part.  The  postero-dor.sd  margin  is  ornamented  with  strong  nodose 
ridges. 


180  ("KE'rACEOUS    L  \:\!ELLIliRANCHIA. 

Mea^-uremeids  .- 

(1)  (2)  (3) 

Length         .         80         .         70         .         69  ram. 
Height  .         44         .         39         .         36    „ 

(1 — 3),  Perna-hed,  Atherfield. 

Afjlnities. — Forl)es  states  that  English  examples  of  this  species  were  identified 
bv  comparison  with  French  specimens.  I  have  not  seen  any  foreign  examples  of 
P.  Uohhidhlina,  but  the  English  specimens  appear  to  differ  from  those  fignred  by 
(r()il)igny  and  by  Pictet  and  Campiche  in  their  greater  convexity  and  larger  size, 
in  the  more  acnte  angle  wliieli  the  ribs  make  at  the  dorso-ventral  line,  and  in  the 
somewhat  less  anterior  position  of  that  line.  In  all  these  respects  the  English 
examples  approach  more  nearly  to  /'.  iieoromiensk  (de  Loriol),'  bnt  differ  from  that 
species  in  their  more  elongate  form.  It  seems,  however,  not  nnlikely  that  a  large 
nnmber  of  specimens  might  show  that  1\  liohinaldina  and  /'.  ii/'ocomicnsh  are  not 
specifically  distinct.  In  connection  with  this,  attention  may  ])e  called  to  Nnctthi 
(Acila)  bivirgafa,  Sowerby,  in  which  the  ornamentation  is  somewhat  similar  and 
shows  considerable  variation. 

The  genus  Pti/chomi/a  was  placed  in  the  Crassatellitida^  by  Pictet  and  Cam])iche 
and  by  Stoliczka.  Its  resemblance  to  Circe  (Criifa)  was  pointed  out  and  fully 
discussed  by  Dames,"  whose  view  of  its  systematic  position  is  accepted  by  Fischer. 

Remarks. — The  date  of  the  plate  on  which  Agassiz  figured  rti/chomya  plana  is 
earlier,  but  the  text  relating  to  it  is  later  than  d'Orbigny's  figure  and  description 
of  Grassatella  Rohinaldina.  Since  the  specimen  figured  by  Agassiz  is  rather 
unsatisfactory  and  d'Orbigny's  name  has  been  used  by  nearly  all  writers  it  seems 
desirable  to  retain  the  latter. 

Dkirihntion. — Lower  Greensand  (/Vr;irt-bed)  of  Atherfield.  Ferruginous 
Sands  of  Shanklin.     Hythe  Beds  of  Hythe,  Lympne,  and  Maidstone. 

1  Pictet  ami  Campiche,  "Terr.  Crct.  Ste.  Croix"  ('Mater.  Tal.  Suisse,'  ser.  4,  18(JG),  p.  855, 
pi.  cxxvii,  fi<fs.  9 — 12. 

-  '  Zeitscbr.  d.  dcutscL.  geol.  Gesellscli.,'  vol.  xxv  (1873),  p.  374',  i)l.  xii,  figs.  1 — 4. 


Ipalcxontoorapbical   Socict\>,  1908. 


A     M()X()(;  RAPH 


OF    THE 


CRETACEOUS    LAMELLIBliANCHL^ 


ENGLAND. 


HENRY  WOODS.  M.A. 

DNIVERSITT    LECTUREE    IN    PAL.BOZOOLOUT,    CAMBRIDOE. 


VOL.  IL     PART  V. 

VENERID.E,  CARDIID.E,  DICER ATID.E,  MONOrLEURID/E,   AND 

CORBULID.E. 

Pages  181—216;   Plates  XXVIII— XXXIV. 


L  O  .\  D  O  N  : 
PRINTED     FOR     THE     PAL^ONTOG  RA  l"  HI  0  A  L     .SOCIETY. 

1908. 


BBIKTED    BY    ADLAKD    AND    SON,    LONDON    AND    DORKING. 


l)()SIN10l'SJ8.  iyl 


(Innis — DdsiNlor.sis,     T.    .1.     ('(iiiniJ,    IHlJI. 
('  I'roc.  Acad.  Nat.  Sci.  Pliila-ai-lpliia,'  |).  -JllJ.) 


DoSINIOl'SIS    SUliEOTUNl>.\    {Soirrrhlj),    1 830.       I'latu   XXVIII,    lig.S.    1  — (J. 

1836.     Cythkb«a  subkotunda,  ,/.  de  C.  Sowerby.     Trans.  Geol.  Soc,  ser.  2,  vol.  iv, 

pp.  240,  :3-il,  pi.  xvii,  tig.  2. 
1850.     Venus  —  A.  cVOrhUjnij.     Prodr.  de  Pal.,  vu\.  ii,  p.  159. 

1854.     Cythkkea  —  J.  Morris.     Cat.  Biit.  Foss.,  ed.  2,  p.  201. 

1870.     Venu.s  —  /*'.  Sluliczka.      Paleeout.    ludica,   Cret.    Fauua  S. 

India,  vol.  iii,  p.  161  (Caryalis). 

Description. — Shell  rather  thick,  rounded,  oval  or  somewhat  orbicular,  of  small 
or  moderate  convexity ;  length  rather  greater  than  height ;  moderately,  sometimes 
considerably,  inequilateral.  Antero-dorsal  margin  long,  concave.  Anterior 
margin  rounded,  passing  gradually  into  the  considerably  curved  ventral  margin. 
Postero-dorsal  margin  very  long,  convex,  witli  a  considerable  ventral  slope. 
Posterior  margin  rounded.  Umbones  small,  pointed,  close  together,  slightly 
curved  anteriorly.  Lunule  elongate,  depressed,  distinctly  limited.  Escutcheon 
narrow,  depressed,  with  a  sharp  border.  Pallial  sinus  rather  large,  sub-angular. 
Ornamentation  consists  of  fine  concentric  striae,  and  growth-lines. 

Hinge  :  In  the  right  valve  three  strong,  nearly  straight,  diverging  cardinal 
teeth,  of  which  the  anterior  and  median  are  closer  together  and  diverge  at  a 
smaller  angle  than  the  median  and  posterior,  the  last  being  divided  l)y  a  shallow 
longitudinal  groove;  there  is  a  small  posterior  lateral  tooth  and  an  elongate 
anterior  pit.  In  the  left  valve  the  anterior  of  the  three  diverging  cardinal  teeth  is 
nearly  vertical,  the  median  is  the  stoutest,  and  the  posterior  is  oblicjue  and  slender ; 
the  anterior  lateral  tooth  is  elongate  and  pai'allel  to  the  lunular  margin;  the 
posterior  lateral  is  very  small. 
Measure  1)1  cuts  .- 

(1)  (2)  (y)  (t)  (5) 

Length     .         34         .         31  .         2\)         .         28         .         20      mm. 

Height     .         32         .         28         .         20-5      .         20         .         2:3-5      „ 

(1 — 5j  Blackdowu. 
Ti/pe. — From  Blackdowu;  in  the  Bristol  Museum. 
Distribnilon. — Upper  Greensand  (zone  of  Srlduiubuchia  ro.slndu)  of  Blackdown. 


24 


182  CRETACEOUS    l.AMELLIIiliANCll  lA. 


DdSiN-K.i'si.s  cAi'KiJATA  (Suin'rhj/),  18:2(5.      I'late  XXVI 1 1,  tigs.  7— JU. 

1826.     Venu.s  capkkata,  J.  de  C  Sowerhi/.     Miii.  CoiilIi.,  vol.  vi,  j).  ol,  [il.  ilxviii, 

figs.  IS. 
18.50.         —  ~  A.  d'Orhlijitij.     Prodr.  de  Pal  ,  vol,  ii,  \,.  159. 

1854.     Cytheuea    —  J.  Morris.     Cat.  Brit.  Poss.,  cd.  2,  p.  200. 

18(j5.     Venus  capekata,    F.   J.   Fidel  and  0.   Camjnche.     Poss.  Terr.   Crct.   Ste. 

Croix  (Mater.  Pal.  Suisse,  ser.  4), 
p.  189. 
lst;8.  —  —  .1.  liridrl  ami  F.   L.   Cornet.       Meule    de    Bracquegnies 

(Mem.    cour.    et    Mem.    des    Sav. 
elrangers,    vol.    .\.\.\iv),    p.   74,  pi 
vii,  figs.  6 — 8. 
1870.         —  —  /•'.  Shdli-Aa.      Paheuiit.  In.lica,  Cret.  Paumi    S.    ludia, 

vol.  iii,  p.  1(10  {Caryatis). 

V  Noll   |S|.-,.  —  —  A.  d'Orh'iijiiij.      Pill.    Fraiie    Terr.   Cret.,  vol.   iii,   p.  445, 

pi.  eeel.\.\.\v,  tigs.  9,  10  ( 1'.   iiiiljijniiin. 
Prodr.  de  Pal.,  vol.  ii,  p.  236). 

Ih:sfrij)lii>)i. — Sliell  oval,  conve.x,  uioderately  or  considerably  iHe(|iiilateral ; 
length  ratlier  gieater  than  height.  Antero-dorsal  margin  concave.  Anterior 
margin  rouiuU-d,  pa.ssing  gradually  into  the  convex  ventral  margin.  Posterior  less 
convex  tiian  the  anterior  margin,  sometimes  subtrnncate.  Postero-dorsal  margin 
long,  slightly  convex.  Unibones  pidniinent,  curved  anteriorly.  Ltuiule  ovate. 
Pallial  .■<inn.'^  lat her  large,  sulj-angidar.  Ornamentation  consists  of  strong,  regular, 
concentric  ribs. 

Hinge  :  Tn  the  right  valve  three  stout  cardinals  separated  dorsally,  the  anterior 
and  median  i)eing  close  together  and  nearly  vertical,  the  posterior  obliijue  and 
divided  hy  a  longitudinal  groove  ;  there  is  an  antei'ior  elongate  pit  and  a  strong 
postei-ior  lateral  tooth.  In  the  left  valve  the  median  is  the  stoutest  of  the  three 
cardinals  and  is  sometimes  juincd  dorsally  to  the  neai'ly  vertical  anterior  cardinal; 
the  posterioi- cnnlinal  is  slender  and  \ery  obliipie;  the  anterior  lateral  is  strong, 
elongate  and  ])ar:illcl  to  the  liiiiular  ni;ti'gin. 

Mea.^arciiU'iif.s  : 

(1)  (^)  i-i)  W 

Leugth    .     ot     .     31      .     30     .     128     . 

Height    .     :>0-5.     2'.»     .     2G     .     24.-5 . 

(1     H)  Blaekdown. 
Ui'iimrks. — Internal    castti    from    the    Folkestone    i3eds    of    I'ulborough     were 
referred  to  this  species  by  Forbes.      I  have  not  seen  any  s])ecimens  which  wcndd 
enable  me  to  record  the  oeeurri'nee  of  l'.  cupcrata  in  the  Lower  Creensand. 


{■>) 

(li) 

(') 

W 

2() 

.     2o     , 

.     21     . 

15  mm 

22 

.     23     . 

18-5. 

14     „ 

CYPRIMKRIA.  183 

'I'lipc. — From  Blackdown  ;  in  the  British  Museiiin. 

Disfribittioii. — Upper  (Treensixnd  (zone  of  SrJilonihachia  rosfrafd)  of  Bhickdown 
and  Haldon.  Recorded  by  Barrois  from  the  Upper  Greensand  of  Liilwortli,  and 
by  Jukes-Browne  from  the  Upper  Greensand  of  the  Isle  of  Wight. 


Genus — ("yimmmeria,  T.  A.  Conrad,  18G4. 

(•Proc.  Acad.  Nat.  Sci.  Philad.,'  18G4,  p.  212,  aud  '  Amer.  Journ.  Couch.,'  vol.  ii,  ]8CS,  p.  102. 
Stoliczka,  '  I'alieout.  ludica,  Cret.  Fauna  S.  lu.lia,'  187li,  p.  157.)' 

Suh-ffeniis — Cyclorisma,  IF.  //.  Dall,  1903. 

('Proc.  U.S.  Nat.  Mus.,'  vol.  x.xvi,  1903,  p.  357.     Syu.  CyclothyrU,  T.  A.  Conrad  in  W.  C.  Keir's 
'Geol.  Rep.  N.  Carolina,"  vol.  i,  Appendi.K  1  (1875),  p.  8.     Non  CyclotJiyris,  M'Coy,  1844.) 


CYri(iMKi;i.\  (Cvclouisma)   vectensis  (Forhrs),  1845.     Plate  XXVIH,  tigs.  11—18. 

1845.     Venus  vectensis,  E.  Forbes.     Quart.  Journ.  Geol.  See,  vol.  i,  p.  240,  pi.  ii, 

fig.  4. 
18.50.         —  —  A.iVOrhiiiny.     Prodr.  de  Pal,  vol.  ii,  p.  118. 

1854.         —  —  ./.  Morrh.     Cat.  Brit.  Poss.,  ed.  2,  p.  231. 

1805.         —  —  F.J.  Firtrl  and  a.  Campiche.      Foss.  Terr.  Cn't.  Ste. 

Croix  (Mater.  Pal.  Suisse,  .ser.  4), 
p.  188. 
1870.  —  F.  Stoliczka.     Palteout.  Indica,  Cret.  Fauna   S.    India, 

vol.  iii,  p.  160. 
?  1883.         —  —  W.  Keejjiiuj.     Foss.,  etc.  Neoc.  Upwaro  and  Brickhill, 

p.  125. 

])p!<n-ipfi(in. — Shell  oval,  or  nearly  orbicular,  a  little  longer  than  high,  regularly 
convex,  slightly  or  moderately  inecjuilateral.  Margin  rounded.  L'nibones  small, 
pointed,  somewhat  curved  forwards.  Lunule  indistinct,  not  impressed,  limited  by  a 
Faint  line.  Pallia!  sinus  angiilar,  directed  upwards.  Margins  of  valves  smooth. 
Surface  of  shell  smooth  except  for  small,  inconspicuous,  concentric  ridges,  and 
occasional  growth-rings. 

Hinge :  In  the  riglit  valve  an  anterior  and  a  median  cardinal  and  two  posterior 
laminar  teeth  (which  together  represent  the  posterior  cardinal)  diverge  from 
under  the  umbo;  the  anterior  is  directed  forwards,  the  median  is  nearly  vertical, 

'  'i'he  following  European  species  are  referred  by  Conrad  and  In-  Stoliczka  to  the  j,'cniis 
Cyprimeria:  C yclina primieva,  Zitt.,  Dosivia  cretacea,  Zitt.,  Circe  (liKriin  (Math.),  Circf  cohciiiIiIch, 
Zitt.,  and  AreoiHKjiii  rotinidnf/i,  d'Orb.  Holzapfel  figures  Cypriiiirri'i  (ieinHzi  (Midi.)  and  C.  motiela, 
Holz.,  from  the  Aachen  Greensand. 


184  CRETArEOUS   LAMELLIBRANCHIA. 

and  the  two  posterior  slope  oblicpielv  backwards.  In  the  left  valve  a  long,  oblitpie 
laminar,  posterior  cardinal;  a  median  cardinal  (which  is  divided);  and  an 
anterior  cai'dinal,  diverge  nnder  th(>  ninbo,  from  which  they  are  separated  by  a 
narrow  space  or  channel.  In  front  of  the  anterior  cardinal  the  anterior  part  of 
the  hinge-plate  is  concave. 
Alcd.mrcments  : 

(1)  (2)  (3)  (4)  (5) 

Length     .         38         .         32         .         31         .         28         .         24      mm. 
Height     .         34         .         20-5      .         20         .         2G         .         22-5     „ 

(1—5)  Crackers,  Atherfield. 

Afjiidtirii. — This  species  shows  some  resemblance  to  Vcnvs  rriidoppraiia 
(Leymerie),  especially  to  the  example  figured  by  Pictet  and  Renevier,'  but  the 
umbones  are  less  prominent  and  the  lunide  is  less  distinct. 

l^ypc. — The  type  came  from  the  Crackers  of  Atherfield,  ])nt  cannot  now  he 
found. 

Distriliiifion. — Lower  Greensand  (Crackers)  of  Atherfield.  Recorded  from 
the  Atherfield  Clay  and  Bed  vii  of  Atherfield  by  Fitton.  Recoi-ded  by  Topley 
from  the  Atherfield  Beds  of  Peasmarsh  and  Shalford.- 


Cvn;iMi.;i;]A   (Cvclokism  \)   pakva   {Sowrrh,/),    182(;.      Plate    XXVIII,  figs.  19—23; 

Plate  XXIX,  figs.  1—3. 

1826.     Venus  parva,  J.  de  C.  Sowerhy.      Miu.  Concli.,  vol.  vi,  p.  32,  ]il.  dxviii, 

1845.     LuciNA  >  soLiDULA,  E.  Forbes.    Quart.  Joiiru.  Gi'ol.  Soc,  vol.  >,  ]..  239,  pi.  ii, 

fife'.  7. 
1850.     Venus  parva,  A.  d'Orhiijinj.     Prodr.  dePal.,  vol.  ii,  p.  159  (not  Blackdown). 

—  Llcina  soi.idui.a,  iVOrJiiijinj.     Iliid.,  vol.  ii,  p.  118. 

1854.     Cythkrea  parva,  ./.  Murris.     Cat.  Bnt  Foss.,  e^i.  2,  p.  2(il  (  purfim). 

—  LuciNA  80I.IDULA,  MoriiK      Il)id.,  (d.  2,  p.  208. 

1865.     Venus  parva,  F.  J.  Pictet  ami  G.  Campiche.      Foss.  Terr.  Crcl,  Ste.  Croix 

(Mater.  Pal.  Suisse,  ser.  4),  p.  188. 
1870.         —  —      F.StoUczka.     PalfDont.  ludiea,  Cret.  Fauna  S.  India,  vol.  iii, 

p.  16U  {Ccrryalis). 

—  LuciNA?  solidula  (PMysia),  Stoliczka.     Ibid.,  vol.  iii,  pp.  252,  262. 

?  1895.     Venus  rf.  pakva,  E.  TieKseu.    Zeitsebr.  d.  deutsch.  geol.  Gresellsch.,  vol.  xlvii, 

p.  484. 


1  Pict«t  and  Kencvier.  '  Foss.  Terr.  Aptieu'  ('  Mati'r.  Pal.  Suisse,'  ser.  1,  1855-56),  p.  71,  pi.  vii, 
%  9.  Pictet  :ind  Canipiclie,  'Terr.  Crct.  Ste.  Croix'  ("Mat^r.  Pal.  Suisse,'  ser.  4,  1865),  p.  l«l.pl.cxi, 
fi-   12. 

~   r  liave  not  seen  the  specimen  recorded  l)\-  Kei'pin>,'  tiiim  Upware. 


CYPRTMERIA.  185 

Non  1840.     Venus    pauva,   A.  GoJdfiiss.     Pctref.   Germ.,  vol.  ii,  p.  246,  pi.  cli,  fif;.  4 

(V.  Goldfufisi,  Qe'nntY.,  1850;    V.  gtihparva, 
d'Orbigny,  1850). 

—  1841.        —  —      F.  A.  Itiimer.     Die  Verstein.  d.  nord-deutsch.  Kreidefjeb., 

p.  72  (Venus  snhinflexa,  Kiiiner,  1836). 

—  1846.         —  —     A.  E.  Reiii>s.     Die  Verstein.  der  bfihm.  Kreideformat.,  pt.  2, 

p.  20,  pi.  .xli,  figs.  16,  17. 

—  1863.        —  —     A.  V.  Sfromheck.     Zeitschr.    <ler   deutsch.    gfol.    GesclLsch., 

vol.  XV,  p.  146. 

—  1868.         —  —     A.  Briaii  and  F.  L.  Cornet.    Meule  de  Bracquegnies  (Mem. 

cour.  et  Me'in.  des  Sav.  I'trangcrs, 
vol.  xxxiv),  p.  75,  pi.  viii,  figs.  1,  2. 

—  1877.     Cytherea  PARVA,  G.  l?o/i»!.     Zeitschr.  der  deutsch.  geol.Gesellsch.,  vol.  xxix, 

p.  241. 

—  1883.     Vencs  cf.  PARVA,  A.  Fritsch.     Stud,  im  Gobicte  der  biihm.  Kruidefurniat.,  iii, 

Iserschicht.,  p.  109,  fig.  77. 

—  1885.     Venus    parva,  F.  JViifliiui.     Die  Fauna  d.   baltisch.  Cenoman.    (PaliEont. 

Abhandi.,  vol.  ii),  p.  32,  pi.  v,  fig.  11. 

—  18fl3,         —  —      Fritsrii.     Op.  rit.,  V,  Priesen.  Sehicht.,  p.  98,  fig.  118. 

Descriptidji. — Shell  small,  nval,  convex,  inoileratcly  inequilateral.  Antero- 
(lorsal  margin  slightly  concave,  or  nearly  straight,  forming  a  rounded  angle  with 
the  anterior  margin  which  curves  rapidly  to  join  the  convex  ventral  margin. 
Posterior  margin  rounded  or  .subtruncate.  Postero-dorsal  margin  slightly  convex. 
Umbones  rather  prominent,  curved  inwards  and  forwards.  liunule  broad,  ovate, 
more  or  less  projecting,  limited  l)y  a  groove.  Pal  Hal  sinus  large,  angular. 
Ornamentation  consists  of  small,  somewhat  irregular,  coucenti'ic  ribs,  and  occasional 
growth-rings. 

Hinge:  In  the  rio-ht  valve  the  antei'ior  and  median  cardinals  are  stout  and 
nearly  parallel,  and  the  two  posterior  teeth  (wdiich  represent  the  posterior  cardinal) 
are  oblique  and  diverging ;  in  front  of  the  anterior  cardinal  is  a  groove,  bounded 
by  a  ridge  above  and  l)elow,  parallel  to  the  inner  margin  of  the  hinge-plate.  In 
the  left  valve  the  antei-ior  and  median  cardinal  teeth  diverge  widely  under  the 
umbo  and  the  posterior  cardinal  is  oblique;  the  anterior  cardinal  is  continued 
forward  into  a  i-idge  along  the  inner  margin  of  the  hinge-plate. 

Measurements  : 

(1)  (2)  (3)  (4)  (5) 

Length    .     20-5  .     21     .     20     .     20     .     Ii) 
Height    .     17     .     17-5.     17-5.     17     .     1<^> 

(1)    P,-rno.-hca,  East   Sliair..rd, 
(2—8)  Crackers,  Atherfield. 
Affinities. — The  differences  between  this  species  and  ('.  {Ct/dorimin)  rofimiKjeiisin 
are  given  below. 

The  foiin  fiom  IJiacquegnies,  which  was  referred  to  Vitnix  jitirrn  by  Hnart  and 
Cornet,  is  less  elongate. 


(«) 

r<) 

(«) 

1() 

.     1  !■    . 

10     nnn. 

1 1-    . 

12     . 

s-o  „ 

186  ('RP:TA(JE0US  lamellirranchia. 

The  hinge  differs  from  tliat  of  other  species  of  Ci/clonsmd  in  that  the  anterior 
tooth  in  tlie  left  valve  is  continued  foi'wards  into  a  ridge  at  the  inner  margrin  of 
the  hinge-plate. 

Liicina?  fiolidiild,  Forbes,  appears  to  be  identical  with  fV??7/.s  parva,  Sowerby; 
the  type  is  missing,  but  other  specimens  which  are  in  the  Museum  of  tlie  Geological 
Society  and  were  probably  identified  by  Forbes,  are  undoubtedly  examples  of 
V.  j)arva.  The  typo  of  Lurinn?  solidiila,  so  far  as  one  can  judge  from  the  figure, 
seems  to  have  been  rather  shorter  than  most  examples  of  Venus  pnrva. 

Venus  Orbignyana,  Forbes,'  from  the  Crackers  of  Atherfield,  is  stated  to  be 
allied  to  T^.  jxirra.  The  type  is  missing,  but  a  specimen  named  T'.  OrJiir/in/aiui  in 
the  Museum  of  the  Geological  Society  a2:>pears  to  he  a  small  example  of  ('i/prina 
Saussuri  (p.  131). 

lismnrks. — Examples  of  this  species  vary  somewhat  in  convexity,  in  relative 
heiglit  and  lengtli,  in  the  proniiuence  and  position  of  the  umbones,  and  in  the 
projection  of  tlic  hmule  at  the  margin  where  the  valves  meet.  The  tj'pes  are 
internal  casts  from  I'arliain,  and  they  agree,  exce])t  in  being  slightly  more  convex, 
with  casts  from  Bast  Shalford,  whei'e  specimens  with  the  shell  preserved  are  also 
found.  The  latter  do  not  differ  from  the  perfectly  preserved  specimens  found  in 
tlie  Crackers  of  Atherfield. 

'I'l/ji''. — From  the  Sandgate  Reds  of  I'liilunn  Park,  in  the  Rritish  Museum. 

Pistrll'ii/idii. — fiower  Greensand  :  /V;y/'^-bed,  Crackers,  and  Red  I--")  of  Ather- 
field. /'('/'//(^-lii'd  of  Sandown.  Allicrlicld  Reds  of  Reasniarsh  and  Slialf'oi'd. 
Sando-ate  lieds  of  I'arliani  Pai-k. 


Cvi'K'iMKi;: A  (Cvcr.oi.MsiMA)  K'oToiMACKNsis  {(V Orhiijii ij) ,  1S45.     IMate  XXIX,  figs.  4 — 0. 

\8^h.      Vknus   iMioToMAiii-.Nsis,  A.  il'<_h-}iiijiiij.      Pal.   FiiUi<;.  Terr.  Cn't.,   vol.  iii,  p. 

443,  ]>1.  ccclxxxv,  fitjs.  1 — 5. 

ISf)!!.  ROTiioMAOKNSis,  (VOrhiijinj.     Prodr.  do  Pal.,  vol.  ii,  ]).  104. 

l.S(;.'').  RoToMAf.KNSis,    F.  J.  Pirlrl  ,1)1(1   G.   Coiiqjichc.      Fo.ss,  Ten-.  Cn't. 

Ste.  Croix  (Mater.  Pal.  Suisse, 
ser.  4),p.  190. 

1870.  -  —  F.    Sf'ilirkza.      Palreont.    Indica,    Cret.    Faiiua-   S. 

India,  vol.  iii,  p.  161  (?  Caryatis). 

RemarJ.-s. — The  Knglish  examples  of  this  sjiecies  are  internal  casts  occasionally 
with  small  portions  of  the  shell  preserved.      l)'()rl)igny's  S})ecimens  were  obtained 

I  -Quiirt.  Joiiin.  (leol.  So.'.,'  vol.  i  (1845),  p.  240,  pi.  ii,  Al,'.  5;  d'Orbigny,  'Prodr.  de  Pal.,' 
vol.  ii  (1850),  p.  118;  Morris,  'Cat.  Brit.  Foss.,'  ed.  2  (1854),  p.  231  ;  Piotet  aud  Campiche,  '  Foss. 
T.'rr.  Cn't.  Ste.  Croix'  ('Mater.  Pal.  Suisse,'  ser.  4.  1865)  pp.  184,  188;  Stoliczka,  '  PalKont.  Indica, 
Cr.'l.  Fauna  S.  India,'  vol.  iii  (]«7()),  p.  ICO. 


CVIMMMERIA.  Iy7 

from  tliL'  tJeiioinaniaii  of  Rouen.  English  specimens  agree  with  tliose  founcl  at 
Rouen,  except  that  in  many  cases  the  shell  is  somewhat  shorter  relatively.  The 
surface  is  ornamented  with  concentric  ribs.  In  I'.  {Ci/cLurisiua)  rotoindt/t'n.slti  thu 
shell  is  more  convex,  more  inequilateral,  and  the  postero-dorsal  margin  has  a 
greater  slope  than  in  C.  {('i/c/iirismd)  jiiirru..      The  hinge  appeal's  to  l)e  uid<no\vn. 

Distribution. — Base  of  the  Chalk  Marl  of  Maitlen  Newton  and  Chard.     Chlorilic 
Marl  of  Melhury,  Woolcondte,  Maiden  Hi';idley  anil  the  Isle  of  Wight.' 


CvriMMKKiA  (Cvi'lokis.ma)    faua   {Soirrrlnj),  1.S27.      IMate  XXIX,  Hgs.  7— 1:J. 

1827.     Venus  v\k\,  J.  dc  C.  Svwt;rhij.     Miu.  Cuiicli.,  vul.  vi,  p.  12!»,  [.Ldlxvii,  fi;,'.  3. 

IS.'iO.         —         —     A.  iVOrh'ujiiij.     I'nxlr.  dePal.,  vol.  i-i,  J..  LW  (^«(Wr»i)- 

1854.         —         —J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  230  (pariivi). 

1868.         —         —     A.  Brlart  and  F.  L.  Curncf.     Meule  de  Bracquej^uius  (Mi'ui. 

cour.  et  Mi''iii.  des  Sav.  I't  rauj,'ers, 
vol.    xxxiv),  J).    73,  j)l.   viii,  tif^s. 

y,  10. 
1870.         —         —     F.  Stoliczlca.     Pul;ioiit.  indica,  Cret.  Fauna  S.  India,  vol.  iii, 

1>.  i(;o. 
1873.         —         —     II.    I).    Ociiiitz.      Das    lilbthalgol>.    iu    Sachseu    (Pala-'outo- 

graphica,  vol.  xx,  pt.  2),  p.  65,  pi.  xviii, 
figs.  9,  10. 
?  1882.         —  J.  Kiesou).     Sclirift.  d.  uat.  (Icsellsch.  iu  Danzig,  N.F.,  vol.  v, 

p.  239. 
!'  1885.         —         —     F.  Niilliitij.      Die    Fauna    <1.    haltisL-li.    Cononian.    (I'alx'out. 

Al)liandl.,  Vol.  ii),  p.  32,  pi.  vi,  tig.  1. 

Non  l.SK).  —     A.  Goldfms.     Petrcf.  Germ.,  vol.  ii,  \<.  217,  pi.  rli,   tig.  ('>  (P. 

xithfidia,  d'Orhigny ). 

—  1843.         —         —     H.  D.  Gcinitz.     Die  Versteiu.  von  Kiesliugswalda,  p.  13,  pi.  ii, 

figs.  7—9. 
'i  —    1845.  —         ~     A.d'Orhhjinj.     Pal.    Pranv.    Terr.    Cret.,    vol.    iii,  p     t-t-t,  pi. 

ccclxx.w,  figs.  G — 8. 
1846  —         —     A.  E.  Eeusa.     Die  Verstein.  der  bohni.  Kreideforniat  ,  |.t.  2, 

p.  21,  pi.  xli,  tig.  12. 

—  1847.  —  —     J.  Midler.     Petref.  der  Aaehen.  Kreidef.,  pt.  1.  p.  24. 

—  1859.         —       iMMEKSA,  Midler.     Ibid.,  Supplement,  p.  13. 

—  1863.  ^       FABA,  A.  V.  Stromheck.      Zeitschr.  d.  deulsch.  geol.   Gesellseli.,   vol. 

XV,  p.  147. 


1  Au  ira^xji-fect  left  valve  from  the  Cenomanian  (Bed  12)  of  Wbitecliff,  South  Devon,  was 
identified  by  C.  J.  A.  Meyer  with  Veiiiig  Goldfiisxi.  Geinitz,  '  Das  Quadersaudst.  oder  Kreidegeb.  iu 
Deutschland  '  (185U),  p.  154,  pi.  x.  figs.  7,  8  ;  '  Das  Elbthalgeb.  iu  Saehseu  '  ('  Palueoutogi-aphicu,'  vol. 
XX,  pt.  2,  1873),  p.  67,  pi.  xviii,  figs.  16,  17.  There  is  not  sulficieut  evidence  to  confirm  this  ideutificu- 
tion  ;  the  anterior  part  of  tlie  specimen  is  more  produced  than  in  the  case  of  the  examples  figured  by 
Geinitz. 


188  CRETACEOUS    J.AMEEI.lJUtANCll  I  A. 

Nou  1803.     Venus  kaba,  H.  Dreschtr.     Ibid.,  vol.  xv,  p.  3-13. 

—  1884.     CrrKiMEKiA  faba,  E.  HohaiiJ'd.     Ibid.,  vol.  xxxvi,  p.  4t)7,  pi.  vii,  fig.  1. 

—  1889.     Tapes  faba,    E.    B.ohai>fel.      Die   MoUusk.    Aaclieu.    Kreide   (Palseonlo- 

i,'r;ipliicii,  vol.  xxxv),  p.  1G5,  pi.  xiii,  figs.  7-lU. 

—  1897.     Venus  (Tapesj   faba,  A.  Fritsch.     Stud,  iiii  Gubiete   dor   boLm.  Kreide- 

forinat.,  vi,  Clilomek.  Schiclit ,  p.  G3, 
fig.  80. 

—  1901.         —  —  —     F.  StufiH.     Jalirb.  d.  k.  preussisch.  geol.  Laudesuust. 

fiir  1900,  vol.  xxi,  p.  82. 

Descriptum . — Shell  oval,  of  moderate  ctjiivexity,  witli  flattened  sides,  con- 
sidei'ably  iiK'{|uilateral.  Antero-dursal  margin  short,  slightly  concave.  Anterior 
margin  rminded,  passing  gradually  into  tlic  sliglitly  convex  ventral  margin. 
Postero-dorsal  margin  long,  slight!}'  convex,  with  a  moderate  or  cousidei'able 
ventral  slope.  Porterior  margin  short,  rounded  or  suhtruncate.  Umbones  small. 
Lunule  elongate,  not  impressed,  faintly  limited.  Ormimentation  consists  of  small, 
regular,  concentric  ribs. 

Hinge:  In  the  right  valve  the  anterior  and  median  cartlinals  are  stout,  diverge 
slightly,  and  are  directed  forwards,  and  reach  the  lower  margin  of  the  hinge- 
plate;  the  two  posterior  teeth  (wliicli  represent  the  posterior  cardinal)  are 
laminar,  oblique  and  diverging.  In  the  left  valve  the  anterior  and  median 
cardinals  are  rather  stout  and  divei'ge;  the  posterior  cardinal  is  slender  and 
obliijue.  In  front  of  the  antei'ior  cardinal  there  is  a  concave  space  on  the  hinge- 
plate  in  hoth  valves. 


Measureme), 

Us : 

(1) 

(2) 

(3) 

(4) 

(5J 

Length 

30 

29 

. 

29 

28 

27  mm. 

Height 

25 

24 

22 

. 

21 

22     „ 

(1- 

-5) 

Blackdown. 

AJJi'iiUies. — 

-Veil UN   An 

■lihli-idiui,    1 

d'Orbi 

igny,'    f 

rom 

the    Seuiinian 

of  Charente 

Inferieure,  is  somewhat  simihii'  in  form  to  ('.  {Cijrlorisina)  j'nlxi,  but  the  surface 
oF  the  shell  is  smooth. 

A  species  found  in  tlie  Aachen  Greensand  has  been  identified  by  Goldfuss, 
Holzapfel,  and  others  with  Sowerby's  I'eiuis  faha,  but  was  regarded  as  distinct  by 
(r()rl)igny  ami  G.  Miillei'.  It  differs  from  Sowerby's  species  in  the  greater 
cui'vature  of  the  ventral  margin  and  the  moiv  pointed  posterior  extremity  ;  also  the 
posterior  teeth  in  the  right  valve  are  less  widely  separated  and  are  more  oblique. 

In  d'Orbigny's  figure  of  Venus  faba  the  ornamentation  is  coarser  than  in  English 
examples,  but  a  s[)ecimen  from  the  Cenomanian  of  Rouen  (one  of  the  localities 
cited  by  d'Orbigny)  differs  but  little  in  this  respect  from  Blackdown  specimens. 

Remarks. — The  principal  variation  consists  in  the  amount  of  the  ventral  slope 
1     i'al.  I'lauv-  Terr.  Crtt.,'  vol.  iii  (1845),  p.  449,  pi.  ccclxxxvi,  figs.  t>,  7. 


CLEMENTIA.  189 

of  the  postez'O-dorsal  margin.  In  the  type  specimen  that  slope  is  small,  so  that 
the  outline  of  the  shell  is  distinctly  oval.  The  position  of  the  umbones  also  varies, 
so  that  some  specimens  are  more  inefjuilateral  than  others. 

Specimens  found  in  the  Gault  of  Black  Ven  ai'e  usually  somewhat  crushed  and 
often  larger  than  Blackdown  examples ;  some  are  more  elongate  and  agree  closely 
with  Vemifs  sublasvis,  Sowerby  (see  below). 

Ti/jje. — From  Blackdown ;  in  the  British  Museum. 

Distrihntion. — Upi)er  Greensand  (zone  of  ScJihMuhuchia  rontratti)  of  Blackdown 
and  (?)  Devizes.     Gault  of  Black  Ven. 

Cyprimeria  (Cyclouisma)  subl^vis  (Soioerhi/),  183G.     Plate  XXIX,  fig.  14. 

18.36.     Venus?  subl^vis,  J.  de  C.  Sowerby.     Traus.  Geol.  Soc,  ser.  2,  vol.  iv,  pp. 

242,  342,  pi.  xvii,  fig.  5. 
1850.  Venus  subl.bvis,  A.  d'Orhiyny.  Prodr.  de  Pal.,  vol.  ii,  p.  159. 
1854.         —  —  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  2.31. 

1870.         —  —  F.  Sloliczka.     Palseont.  Indica,   Cret.  Faima  S.  India, 

vol.  iii,  p.  161. 

BemarJcs. — The  only  specimen  which  I  have  seen  is  the  type.  It  differs  from 
G.  {Gydovisma)  faba  only  in  being  more  elongate,  and  seems  to  be  merely  an 
individual  variation.  Venus  immersa,  Sowerby,^  also  known  by  the  type  only 
(Plate  XXIX,  fig.  15),  does  not  appear  to  differ  from  V.  suhlaimfi.  The  types  of 
both  are  in  the  Bristol  Museum  and  come  from  the  Upper  Greensand  of  Blackdown. 

4 

Genus — Clementia,  ./.  E.  Gray,  18-40. 
('  Synopsis  Brit.  Mus.,'  p.  149.) 

Sub-genus — Flaventi.x,  A.  J.  Jnkes-Browne,  1908. 
('  Proc.  Malacol.  Soc.,'  vol.  viii,  p.  167.) 

Clementia  (Flaventia)  Ricokde^vna  (d'Orbu/ny),  1845.     Plate  XXIX,  figs.  16 — 18. 

1845.     Venus  Eicobdeana,  A.  d'Orbigvy.     Pal.  Franv.  Terr.  Crot.,  vol.  iii,  p.  431, 

pi.  ccclxxxii,  figs.  1,  2. 


1  Sowerby,  'Trans.  Geol.  Soc.,'  ser.  2,  vol.  iv  (1836),  pp.  242,  342,  pi.  xvii.  fig.  6;  d'Orbigny, 
'Prodr.  de  Pal,'  vol.  ii  (1850),  p.  159;  Morris,  'Cat.  Brit.  Foss.,'  ed.  2  (1854),  p.  231  ;  Stoliczka, 
'  Palajont.  Indica,  Cret.  Fauna  S.  India,'  vol.  iii  (1870),  p.  161.  Nou  Venus  immersa,  Midler,  '  Petref . 
der  Aacbeu.  Kreidef.,'  Suj.pleuient  (1859),  p.  13;  Eeuss,  '  Die  Verstein.  der  bohm.  Kreideforniat.,' 
pt.  2  (1846),  p.  20,  pi.  xli,  fig.  11  ;  Kner,  'Denlischr.  d.  k.  Akad.  Wissenscb.  Wieu,  Matli.-Nut.  CI.,' 
vol.  iii  (1852),  p.  311.  \<l.  xvi.  tig.  20. 

25 


I'.H)  CRETACEOUS    LAMELLIBRANCIIIA. 

1850.     Venus  Kicoedeana,  A.  d'Orbiyiii/.     Prodr.  dt-  Pal.,  vol.  ii,  jj.  7(j. 
1855.         —  —  G.  Cotteau.     Moll.  Foss.  de  I'Youne,  p.  (34. 

1865.         —  —  F.  J.  Pldet  uiul  G.  Campiche.     Foss.  TeiT.  Civt.  Ste. 

Croix  (Matt'r.  Pal.  Suisse,  ser.  4), 
p.  169. 
1870.         —  —  F.  Sloliczka.     Palaiout.  ludiai,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  159. 


Deacrijjtioii.— Shell  ovul,  convex  with  flattened  sides,  considerably  inequilateral, 
anterior  part  higher  than  the  posterior  part.  Anterior  margin  regularly  rounded, 
passing  gradually  into  the  slightly  curved  ventral  margin.  Postero-doi-sal  margin 
long,  convex,  with  a  considerable  ventral  slope.  Posterior  margin  short,  oblique, 
forming  a  rounded  angle  with  the  ventral  margin.  LFmbones  broad,  curved 
forwards.  The  part  of  the  shell  behind  a  line  between  the  umbones  and  the 
postero-veutral  angle  slopes  rapidly  from  the  flattened  sides.  Luuule  elongate, 
limited  by  a  groove.     Escutcheon  elongate,  deep,  limited  by  a  sharp  edge. 

Ornamentation  consists  of  sharp  concentric  ridges.  Pallial  sinus  angular, 
somewhat  ascending. 


Measurements  .- 

(1) 

(2)                            (3) 

(4) 

(5) 

Length 

56 

52         .         52         . 

5U 

43  mm 

Height 

47 

40         .         39 

(1)  Atberfield  Beds,  Peasmarsli. 
(2,  5)  Po-Ha-bed,  Atberfield. 

(3)  Hytlie  Beds,  Lympue. 

(4)  Hytlie  Beds,  Pulborough. 

35 

34     „ 

4//i'/'i^"'''*-— English  specimens  difl:'er  from  d'Orbigny's  figure  in  the  more  ra[iid 
ventral  slope  of  the  postero-dorsal  margin.  I  am  indebted  to  Professor  Boule  for 
comparing  photographs  of  specimens  from  the  Lower  Greensand  with  the  examples 
in  the  d'Orbigny  collection  which  appear  to  l)e  the  types,  and  he  states  that  in 
the  latter  the  shell  is  less  elongate  and  the  postero-dorsal  l)order  has  a  greater 
slope  than  in  d'Orbigny's  figure,  consequently  the  photographs  agree  much  more 
closely  with  the  types  than  with  the  figure.  M.  A.  de  Grossouvre  has  been  good 
enough  to  lend  me  a  specimen  of  G.  (Plaventin)  Riconlciinit  from  the  Lower  Aptian 
of  Seignelay,  Yonne,  one  of  the  localities  mentioned  l)y  d'Orbigny,  and  a 
comparison  of  that  with  English  exam})les  leaves  no  doubt  as  to  their  specific 
identity. 

The  generic  position  of  Clement ia  {Vlarentvt)  Rico rdea tut  is  at  present  some- 
what uncertain  since  none  of  the  specimens  shows  the  hinge ;  but  on  account  of 
the  resemblance  in  the  form  of  the  shell  to  that  of  (!.  {Flaventia)  omiis  it  is 
probable    that   this  species  belongs    to  the   sub-genus  Flaventia.     C.    (Flaventia) 


CLEMENT!  A.  191 

Ricordeana  is  less  elongato  and  its  postero-dorsal  margin  is  iiinre  convex  and  slopes 
more  rapidly  than  in  Venns  suh-Brnngninrtiann,  d'Orbigny.' 

Remnrlcit. — This  is  probably  the  species  which  has  been  recorded  by  some 
authors  from  the  Lower  Grreensnnd  as  Vevm^  nvalis  and  Asfarfr  s^vJistrinta,  Leymerie. 
The  proportions  of  length  and  height  vnry  considerably  in  different  specimens. 

Distribution. — Lower  Greensand  (/^'9-»rt-bed)  of  Atherfield.  Atherfield  Beds 
of  East  Shalford,  Redhill,  and  Pensinarsh.  Hythe  Beds  of  Hythe,  Lympne,  and 
I^nlbornnofli. 


Clementia   (Flaventia)  ovams  {Sowerhy),  1827.     Plate  XXIX,  figs.  19— 2*). 

1827.     Ventjs  ovams,  .7.  de  C.  Sowcrhy.     Min.  Conch.,  vol.   vi.  p.  129,  [il.  dlxvii, 

fig.  1  (not  fig.  2). 
18.50.         —  —A.  (VOrhigny.     Prodr.  de  Pal.,  vol.  ii,  p.  159. 

18.54.         —  —       J.  Morris.     Cat.  Brit.  Foss.,  ed.   2,  p.  2S1    (not  from  the 

localities  given). 
1870.         —  —       F.  Stolrczha.     PaliEont.  Indica,  Cret.   Fauna  S.  India,  vol. 

iii,  p.  160. 

Nonl840.  -  —A.  Goldfiiss.     Petref.  Germ.,  vol.  ii,  p    247,  pi.  eli,  fig.  5 

{Venus  subovalig,  d'Orbignj,  18.50). 

—  1846.         —  —       A.  E.  Reuss.     Die  Verstein.  der  biJhm.  Kreideformat.,  pt.  2, 

p.  21,  pi.  xxxiv,  fig.  22. 

—  1847.         —  —       /.  Mailer.     Petref.  der  Aachen.  Kreidef.,  pt.  1,  p.  24. 

—  1870.         —  —       n.  Credner.     Zeitschr.  d.  deiitsch.  geol.  Gesellsch.,  vol.  xx, 

p.  191. 

—  1884.     Cytherea  ovalis,  E.  Holzapfel.     Ibid.,  vol.  sxxvi,  p.  464,  pi.  vii,  figs.  2 — 4. 

—  1888.  —  —       G.  Mailer.     Jahrb.  d.  Ic.  preussisch.  geol.  Landesanst.  fiir 

1887,  p.  427. 

—  1889.  —  —      E.  Holzapfel.     Die   Mollusk.  Aachen.  Kreide  (Palseon- 
^  tographica,  vol.  xxxv),  p.  169,  pi.  xiii, 

figs.  11—15. 

—  —        Venu.s  —      A.  Fritgch.     Stud,  im  Gebietc  der  biihni.  Kreideformat., 

iv,  Teplitz.  Schicht.,  p.  80,  fig.  69. 

—  1898.     Cythehea       —       G.  Mailer.     Mollusk.  d.  Untersen.  v.  Braunschweig  u. 

Ilsede,  p.  66.  pi.  ix,  fig.  15. 

—  1901.  --  —       F.Sturm.     Jahrb.  d.  k.  preussisch.  geol.  Landesanst.  fiir 

1900.  vol.  xxi.  p.  83. 

Z)(?.5ci-i2)<ioH.— Shell  elongate-oval,  of  moderate  convexity,  considerably  inequi- 
lateral.    Antero-dorsal  margin  rather  long,  concave.     Anterior  margin  rounded, 

'  Leymerie,  'Mem.  Soc.  geol.  de  France,'  ser.  2,  vol.  v  (1842),  pp.  5,  25,  pi.  v,  fig.  7;  d'Orbigny, 
'  Pal.  Fran?.  Terr.  Crc't.,'  vol.  iii  (1845),  p.  4:52,  pi.  ci.lxxxii.  figs.  3—6;  Pictet  and  Campiche,  'Terr. 
Crt't.  Ste.  Croix'  (1865),  p.  168.  pi.  cxi,  fig.  1. 


192  CRETACEOUS    LAMET.LTBRANCHIA. 

passing  gradually  into  the  coTisideral)ly  curved  ventral  margin.  I'ostero-dorsal 
margin  long,  convex.  Posterior  margin  sliort,  rounded.  Umbones  prominent, 
pointed,  with  a  considerable  anterior  curvature.     Lunula  ovate,  faintly  limited. 

Ornamentation  consists  of  growth-rings  and  (in  well-preserved  specimens)  of 
numerous  small,  regular,  concentric  ribs.  Pallial  sinus  deep,  ascending,  with 
rounded  end. 

Hinge :  In  the  right  valve  the  anterior  and  median  cardinals  are  strong,  and 
diverge  below  the  iimbo  ;  the  posterior  cardinal  is  long,  oblique,  curved,  and 
divided  into  two  parts  of  which  the  anterior  is  shorter  than  the  posterior.  In 
the  left  valve  the  anterior  and  median  cardinals  are  strong  and  diverge  below 
the  umbo ;    the  posterior  cardinal  is  laminar  and  very  oblique. 

Measurements  : 

(1)  (2)  (:i)  (4)  (5)  (6) 

Length     .     44     .     40     .     37     .     34     .     32     .     30     mm. 
Height      .     33     .     31     .     32     .     2G     .     27     .     23       „ 

(1 — 6)  Blackdown. 

Affinitux. — The  form  from  the  Aachen  Greensand  which  was  referred  to  this 
species  by  Groldfuss  and  others  possesses  an  anterior  lateral  tooth. 

Remarks. — In  Sowerby's  figure  the  lunule  projects  more  than  in  any  specimen 
which  I  have  seen,  l)ut  in  other  respects  the  examples  from  Blackdown  agree  with 
that  figure. 

Type. — The  type  came  from  Blackdown,  but  cannot  now  be  found. 

DistriliuUon. — Upper  Greensand  (zone  of  Schlnmbachiarosfrafa)  oi  Blackdown.' 
Recorded  by  Jukes-Browne  from  the  Upper  Greensand  of  Devizes. 


Genus — Cai.lista,  O.A.L.   Morcli,   1853. 
('Catalog.  Conehvl.  de  Yoldi,'  ii,  p.  27.) 

Callista  plana  (Sowerhi/),  1813.     Plate  XXX,  figs.  1—6. 

1813.     Venus  planus,  .7.  Soircrhij.     Miu.  Couch.,  vol.  i,  p.  58,  pi.  xx,  lower  figures. 
1854      Cytherea  plana,  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  201. 
?  1845.     Venus  plana,   A.  d'Orhiyny.     Pal.  Frauf.  Terr.  Crt't.,  vol.  iii,  p.  4-t7,  pi. 

ccclxxxvi,  figs.  1 — 3  (? partim). 


1  The  type  of  Venus  siihmersa,  Sowcrby,  from  the  Upper  Grroensand  of  Pinhay,  cannot  be  found. 
I  have  seen  no  specimen  which  could  be  referred  to  that  species.  Barrois,  however,  records  it  from 
the  Upper  Greensand  of  Liilwcirth.  .T.  de  C.  Sowerby,  'Trans.  Geol.  Soe.,'  ser.  2,  vol.  iv  (1836),  pp.  242, 
342,  pi.  xvii,  fig.  4  ;  d'Orbigny,  '  Prodr.  de  Pal.,'  vol.  ii  (1850),  p.  159  ;  Morris,  '  Cat.  Brit.  Foss.,'  ed.  2 
(1854),  p.  231  ;  Stoliczka,  '  PaUeout.  ludica,  Cret.  Fauna  S.  India,"  vol.  iii  (1870),  p.  Kil  (Caryatiii) 
Barrois,  '  Terr.  Cret.  Super,  de  TAuglet.  et  do  I'lrelande  '  (187(!),  p.  90. 


CALLISTA.  193 

1850.     Venus  plana,  A.  d'Orhignij.     Prodr.  de  Pal.,  vol.  ii,  p.  159. 
1866.         —  —       F.  J.  Pictef  and  G.  Cawjnche.     Foss.  Terr.  Cn't.  Ste.  Croix 

(Matur.  Pal.  Suisse,  ser. 
4),  p.  190. 
18G7.         —  —       E.  Gueraiujcr.     Album  Pak'ont.  de  la  Sartho,  p.  IS,  pi.  xvii, 

fig.  11. 
1868.         —  —       A.  Briiirt  aniJ  F.  L.  Cornet.     Meuli'de  Bracquegnies  (Mem. 

cour.  et  Mem.  des  Sav. 
(■trangers,  vol.  xxxiv),  p.  72, 
pi.  viii,  figs.  3 — 5. 

?  Nou  1846.     Venus  plana,  A.  E.  Revss.     Die  Ver.stein.  der  bdhm.  Kreideformat.,  pt.  2, 

p.  21,  pi.  xli,  fig.  14. 

?    —     1879.     Cytheeea  (Cabtatis)  plana,  /.  F.  Whiteaves.     Mesoz.  Foss.,  vol.  i  (Geol. 

Surv.  Canada),  p.  149, 
pi.  xvii,  fig.  14. 

Description. — Shell  oval,  sometimes  more  or  less  triangular,  rounded,  moderately 
convex,  considerably  inequilateral ;  length  greater  than  height.  Antero-dorsal 
margin  long,  concave.  Anterior  part  of  valve  more  or  less  produced,  with 
rounded  margin.  Ventral  margin  forming  a  considerable  curve.  Posterior  margin 
short,  rounded  or  slightly  truncate.  Postero-dorsal  margin  convex,  much  longer 
than  the  antero-dorsal  margin.  Umbones  rather  prominent,  pointed,  close 
together,  curved  anteriorly.  Lunula  long,  cordiform,  distinctly  limited. 
Escutcheon  not  defined.  Ornamentation  consists  of  small  concentric  ridges,  with 
stronger  growth-ridges  at  intervals.  Fine  radial  ril)bing  is  occasionally  seen  in 
tlie  posterior  part  of  well-preserved  specimens.  Pallial  sinus  fairly  large,  angular 
or  sub-angular,  slightly  ascending. 

Hinge :  In  the  right  valve  the  anterior  and  median  cardinals  are  nearly 
vertical,  slightl}'  diverging,  and  separated  dorsall}^  the  posterior  cardinal  is 
oblique,  long  and  divided,  its  posterior  part  is  much  longer  than  the  anterior  part, 
and  the  latter  nearly  meets  the  anterior  cardinal  under  the  unil^o ;  in  front  of  the 
cardinal  teeth  there  is  a  shallow,  elongate  pit  with  slightly  raised  upper  and  lower 
margins.  In  tlie  li>ft  valve  the  stout  anterior  and  median  cardinals  diverge  from 
mider  tlie  uinl)o,  tlie  anterior  tooth  l)eing  nearly  vertical;  there  is  a  long  slender, 
obli(|ue  posterior  cardinal,  and  an  elongate,  ridge-like  anterior  lateral  tooth,  wliich 
is  grooved  or  corrugated. 

Measiirr})ii')ifs  .- 

(I)  (2)  (H)  (4)  (-.)  (C)  (7)  (8)  (9) 

Lengtli     .       72       (i'.»       CO       Crl       M       r,2        1-8       4I.       35  mm. 
Hciglit     .       r,3       .-,7       53       51       4.()       43        M        37       29     „ 

(1—9)  Blackd.nvii. 

Al}i)iitirs. — Specimens  from  Senonian  deposits  of  Kurope  have  been  referred  to 


194  CRETACEOUS   LAMELTJRRANCHTA. 

Venus  flamiii,  Sowerby,  by  several  authors;  '  and  so  far  a.s  I  can  jiulgo  from  the 
few  figures  which  liave  been  puljlislied,  tliey  seem  to  differ  but  little  from 
Sowerby's  species.  The  example  from  Aachen  figured  by  Goldfuss  agrees  closely 
with  specimens  from  Blackdown  except  that  the  bniiilc  projects  more  at  the 
margin.  Holzaj^fel  has  compared  Aachen  with  Blackdown  specimens,  and 
confirms  Goldfnss's  identification.  The  example  figured  liy  d'Oibigny"  differs 
in  having  a  large  and  deep  escutcheon. 

Specimens  from  the  Ti-ichinopoli  Group  (near  the  base  of  the  Ariyalur  Gi'oup) 
were  identified  by  Stoliczka'^  with  Vmvs  flavva. 

The  absence  of  a  channel  under  the  anterior  right  cardinal,  and  lh(>  occurrence 
of  fine  i-adial  ornamentation  connect  this  species  with  Gallista.  The  pallial  sinus, 
however,  resembles  that  of  Pifuria.  The  anterior  lateral  tooth  in  the  left  valve  is 
much  less  prominent,  and  the  corresponding  pit  in  the  right  valve  much  smaller 
and  shallower  than  in  either  CaUisfa  or  Pitaria.  This  species  is  the  type  of  the 
section  or  sub-genus  CaUutwa,  Jukes-Browne.* 

Remarks. — This  is  a  common  fossil  at  Blackdown.  The  variations  seen 
consist  in  the  proportion  of  height  to  length,  the  more  or  less  triangular  or  oval 
outline,  and  the  more  or  less  produced  anterior  part  of  the  shell. 

Tyj)e. — From  Blackdown ;  in  the  British  Museum. 

Bit^frUndinn. — Upper  Greensand  (zone  of  SchloonhacJiin  rostrafn)  of  Blackdown 
and  Haldon.  Recorded  by  Jukes-Browne  from  the  Upptn-  Greensand  of  Devizes, 
the  Isle  of  AViffht,  etc. 


o 


Family— CATIDUDJE,   Lamard-. 

Genus — Protocardia,   E.  Beyrirh,  1845. 
('  Menke's  Zeitschr.  f.  Malakozool.,'  p.  17.) 

PijoTOCATMMA  ANfiMOA,  sp.  nov.     Plate  XXX,  figs.  7  n,h;  Plate  XXXT,  fig.  1. 

Descripfiini. — Shell  large,  convex,  with  flattened  sides,  sulxpiadrate,  luoderately 

1  Goldfuss,  '  Petref.  Germ.,'  vol.  ii  (1840),  p.  2:i8,  pi.  cxlviii,  fig.  4  ;  Miiller,  '  Petref.  der  Aiuheii. 
Kreidef.,'  (1847),  pt.  1,  p.  25;  Dresclier,  'Zeitschr.  d.  deutsch.  geol.  Gesellsch.,'  vol.  xv  (186-3).  p. 
344;  Brauns,  '  Zoitsclir.  f.  d.  tjesammt.  Naturwiss.,'  vol.  xlvi  (1876),  p.  308;  II.  SchWidor.  'Zeitschr. 
d.  deutsch.  geol.  Gcsdlsch.,'  vol.  xxiv  (1882),  p.  27.T ;  Holzapfel,  'Die  MoUusk.  Aachen.  Kreide' 
(' Palseoutograpbica,'  vol.  xxxv,  1889),  p.  171,  ]il.  xiii,  figs.  16 — 18;  Vogel,  '  Holland isch.  Kreide' 
(1895),  p.  42. 

2  D'Orbiguy  subsequontlv  separated  the  Senouiau  form  under  I  lie  name  Venn))  suhpIaiKi.  '  I'ludr. 
de  Pal.,'  vol.  ii  (1860),  p.  237.     See  also  V.  Renavxiava,  d'Orbigny,  ibid.,  p.  194. 

•■*  Stoliczka,  'Palseont.  Indica,  Cret.  Fauna  S.  Indi;!,'  v<.l  iii  (1870),  ]>p.  151,  ICO,  li;9,  pi.  vii.  figs. 
1—4. 

^  Proc.  Malacol.  Soc,  vol.  viii  (1908),  p.  156. 


PROTOCARDIA.  195 

inequilateral,    luugtli    and    height    nearly    equal.      Antero-dorsal    margin    nearly 

straight.     Anterior    margin  convex,  curving  rapidly  to  join  the  ventral  margin, 

which  is  moderately  or   slightly  convex.     Posterior    margin    truncated,   forming 

angles  with    the    ventral    and    postero-dorsal    margins.     Umbones    large,    curved 

forwards,  with  a  sharp  carina  extending  in  a  curve  to  the  postero-ventral  angle 

and  limiting  the  flattened,  steeply-sloping  posterior  area,  the  dorsal    portion    of 

which  is  concave.     Shell  depressed  in  front  of  the  umbones. 

Ornamentation  :  Sides  of  shell  nearly  smooth  except  for  numerous,  \evy  small, 

concentric    ribs  which  are  separated  by  fiat  interspaces.     The  posterior   area   is 

covered,  except  near  the  postero-dorsal  margin,  by  12  strong  radial  ribs. 

MeiiHuremeuts  : 

(1)  (^)  (3) 

Length       .         80         .  7G         .  46  mm. 

Height       .         78         .         71)         .         40     „ 

(1 — 3)  Crackers,  Atherfield. 

Acuities. — This  species  resembles  J'.  Forhesi  (Pictet  and  Renevier),^  from  the 
Lower  Aptian  of  Ste.  Croix,  but  the  umbones  are  less  prominent,  and  the  ribs  on 
the  posterior  area  are  less  numerous. 

It  is  also  similar  to  P.  iiu.jjre^sa  (Deshayes),~  but  is  distinguished  by  the 
smaller  curvature  of  the  ventral  margin,  the  greater  flattening  of  the  sides  of  the 
shell,  and  the  more  considerable  curvature  of  the  umbones. 

Distribatioii. — Lower  Greensand  (Crackers)  of  Atherfield.* 


PiiOTorAuniA  spn.KROiOEA  {Forbes),  1815.     Plate  XXXI,  tigs.  2,  S. 

1845.     Caedium   sPHasRoiDiUM,    E.    Forbes.     Quart.    Jouru.    Guol.    Soc,    vol.    i, 

\i.  243.  pi.  ii,  fig.  8. 
1850.  —  —  A.  iVOrhujiiij.     Prodr.  de  Pal.,  vol.  ii,  p.  79. 

1852.  —         NECKEKiANUM,    F.   J.  Fictiit  uiid   \V.  Roiix.      MoU.    Foss.    Ores 

verts  de  Geneve,  pp.  424, 
425,  pi.  XXX,  fig.  3. 
—  —  si'UJiuoiDKUM,  Fidft  and  Roax.     Ibid.,  p.  546. 

1854.  —  —J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  193. 

1  'Foss.  Terr.  Aptien '  ('Mater.  Pal.  Suisse,'  ser  1,  1856),  p.  79,  pi.  viii,  fig.  4;  Pictet  aud 
Caiiipiuhc,  'Terr.  Crct.  Ste.  Croix  (Matur.  Pal.  Suisse,  ser.  4,  18(50),  p.  261. 

^  D'Orliiguy,  -Pal.  Fraut.  Terr.  Cret.,'  vol.  iii  (1841.),  p,  20.  pi.  ccxl ;  Pictet  aud  Caiupiche, 
op.  cit.,  p.  249. 

*  Some  specimeus  of  Protocardia  t'rojn  the  Lower Greeusand  of  Atherfield  were  referred  by  Forbes 
to  Cardium  peregrinorsum,  d'Orbiguy,  but  that  ideutificatiou  was  doubted  by  Pictet  and  Campiche. 
The  speciuicus  at  present  available  arc  iusufficieut  for  exact  deteruiinatiou.  See  Forbes,  *  Quart. 
Jouru.  Geol.  Soc.,'  vol.  i  (1845),  p.  243. 


(.1) 

(5) 

G9 

47  mm. 

87 

48      „ 

ion  CRETACEOUS    I.AI^IKTJJI'.RAXdlTA. 

185{).     Caudium   spiia;koideum,  F.  J.  I'irtd  and  E.  Renevier.     Foss.  Terr.  Aplicu 

(Mati'r.  Pal.  Suisse,  ser.  1), 
p.  77,  pi.  ix,  fig.  3. 
1866.  —  —  F.  J.  I'ictet  and  G.  Cumpiche.     Foss.  Terr.  Cn't. 

Ste.  Croi.x  (Mati'r.  Pal.  Suisse, 
ser.  4),  p.  260. 
1871.  —  —  {y  JjM\icaruivm),  F.Stuliczka.    Palseont.  Indica, 

Cret.  Fauna  S.  India, 
vol.  iii,  ]i.  '213. 

Dt'^crvption. — Shell  stdut,  lai'L;t',  iiiucli  iiitlatcd,  liio-lioi-  tlian  long,  slightly 
inequilateral.  Anterior  and  ventral  niai'gins  rounded.  i'o.sterior  niai'gins  trun- 
cated, forming  angles  with  the  postero-dorsal  and  ventral  margins.  Umbones 
prominent,  with  a  small  forward  curvature,  and  an  inconspicuous  carina  extending 
to  the  postero-ventral  angle  and  limiting  the  flattened  postero-dorsal  area. 

Ornamentation  consists  of  regular,  broad,  flat,  concentric  ribs  separated  by 
narrow  grooves.     On  the  posterior  area  strong  growth-ridges  are  present. 
Measurement  a  : 

(1)  (^)  (3) 

Length     .         79         .         76         .         73         . 
Height     .         84         .         91         .         87         . 

(1—5)  Pcrna-hiiCi,  Isle  of  Wight. 

Affinities. — Pictet  and  Campiche  state  that  this  species  is  very  near  to 
C.  imhricatarium  (Deshayes),^  but  that  the  posterior  area  is  more  flattened  and 
forms  an  angle  with  the  sides  of  the  shell ;  also  the  truncated  posterior  margin  is 
relatively  longer. 

Remarks. — In  this  species  the  radial  ornamentation  of  the  posterior  area  is 
either  very  indistinct  or  quite  obsolete.  There  is  considerable  variation  in  I'elative 
height  and  length  of  the  shell. 

Type. — From  the  Lower  Greensaud  {rcriui-hed)  of  Saudown  ;  in  the  Museum 
of  the  Geological  Society. 

Distribution.  —  Lower  Greensand  {Fcnia-htid)  of  Atherfield  and  Saudown. 
Recorded  by  Topley  from  the  Hythe  Beds  of  Hythe. 

Pbotocaedia,  sp.     Plate  XXXI,  flg.  4. 

The  collection  of  Upper  Greensand  fossils  made  by  the  late  W.  Vicary,  which 
is  now  in  the  British  Museum,  contains  two  imperfect  right  valves  (No.  L  17041) 

1  D'Orbigny,  '  Pal.  Franc;.  Terr.  Crct.'  (1844),  vol.  iii,  p.  18,  pi.  ccxxxix,  figs.  4 — 6;  Leymerie, 
'Mem.  Soc.  geol.  de  France,'  ser.  2,  vol.  v  (1842),  p.  4,  pi.  v,  tig.  2;  Pictet  and  Campiche,  'Terr. 
Cret.  Ste.  Croix'  ('Mater.  Pal.  Suisse,'  ser.  4,  1866),  p.  258,  pi.  cxxi,  figs.  6,  7.  The  specimens  referred 
to  C.  imhricatarium  by  Forbes  are  examples  of  Unicardium  vectense  (p.  163)  ;  see  Forbes,  '  Quart. 
Journ.  Ueol.  Soc.,'  vol.  i  (1846),  p.  243. 


PROTOCARDIA.  197 

from  Haldon,  wliicli  resemble  in  sliape  the  higher  forms  of  P.  ffpliseroidea,  but  the 
umbones  are  narrower  and  more  curved,  and  tlie  carina  is  more  distinct. 
Better  specimens  are  needed  before  a  satisfactory  comparison  can  be  made.  The 
occurrence  of  F.  sphseroidea  in  the  Upper  G-reensand  (zone  of  Pecten  asper)  of 
Wihshire  has  been  recorded  by  Mr.  Jukes-Browne. 


Protogaudia,  sp.     Ph^te  XXXI,  fig.  5  a,  b. 

Description. — Shell  globose,  witli  rounded  outline,  slightly  inequilateral,  height 
and  length  nearly  eipial.  Umbones  low,  curved  anteriorly.  The  posterior 
part  of  the  shell  (except  near  the  postero-dorsal  margin)  is  ornamented  with  from 
ten  to  twelve  strong  radinl  ribs;  the  remainder  of  the  shell  bears  numerous,  small 
concentric  ribs. 

Ajfinitie.i. — This  species  resembles  P.  peregrinorsa  (d'Orbigny),^  but  the  area 
with  radial  ribs  is  relatively  larger,  and  the  concentric  ribs  are  finer. 

Remarkx. — The  only  specimens  seen  are  two  iu  the  Museum  of  Practical 
Geology  and  two  in  Mr.  Lamplugh's  collection. 

Dititriliiiiinn. — Speeton  Clay  (zone  of    Pelemnites  latendi.i,  D,  4)  of  Speeton.- 


PuoTOCAiiDiA  Hii.LANA  {Soioerbij),  1813.     Plate  XXXI,  figs.  G  a—c ;  Plate  XXXII, 

fig.  1—0. 

1813.      Cakdium    Hillanum,    J.    Sowerly.     Miu.    Couch.,    vol.  i,    p.    41,    pi.    xiv 

(upper  figure). 
1819.  —  —  Lamarrk.     Hist.  u;it.  Auiiii.  sans  Vert.,  vol.  vi,  p.  20. 

1837.  —  —A.  Goldfuss.     Petret.  Germ.,  vol.  ii,  p.  220,  pi.  exliv, 

fig.  4. 
—  —  —  F.    Dujardin.     Mum.  Soc.  gcol.  de  France,  vol  ii 

p.  224. 

1840.  —  —  H.    B.   Geliiitz.     Char.  d.  Schicht.   u.   Petrcf.  des 

siichs.  Kreidegeb.,  pt.  2,  p.  53. 

1841.  —  -  F.    A.    Riimer.      Die  Verstein.    d.   nord-deutsch. 

Kreidegel).,  p.  71. 

1842.  —  ]\KtiUKNiAisui\],    r.    Matlnron.       Catal.    Foss.    du    Depart,    des 

Bouches-du-Rhone,    p.    157, 
pi.  xviii,  fig.  6. 


'  'Pal.   Fran^.  Terr.  Cret.,'  vol.  iii  (1844),  p.  1(!,  pi.  cixxxix,  figs.  1 — 3;  Pictet  and  Campiche, 
•  Terr.  Cret.  Ste.  Croix '  ('  Mater.  Pal.  Suisse,'  ser.  4,  1866),  p.  254,  pi.  cxxi,  figs.  1,  2. 

-  Internal  easts  of  a  globose  and  nearly  e(|uilater:il  "  Canlium"  (perhaps  ProtocanUn),  from   the 
Spilsby  Sandstone  ot  Douniugton,  are  in  the  Sedgwick  Museum. 

2G 


1«J8  CliETA{!EUUS   LAMELIJHRANCHIA. 

1843.  Cardium   Hillanusi,  II.  B.  Geiuitz.      Die  Verstcin.  voii   Kieslingswalda, 

p.  13,  pi.  ii,  tigs.  10,  11. 

1844.  —  —A.    d'Orhhjnij.       Pal.   Frauy.  Terr.  CnH  ,  vul.  iii,  p. 

27,  pi.  cfxliii. 

1845.  Pkotocardia  Hii.i^A.tiA,  E.  Bayrich.     Meuke'sZeitsclir.  f.  Malakozool.,  p.  18. 

1846.  —  —         A.  E.  Kftisn.      Die   Versteiu.    dor    buhui.    Kreide- 

format.,    pt.    2,   p.   22,   pi.  xlv, 
fig.  2. 

—  —  —         II.    Ii.    Griiiitz.      Griiudr.    d.    Versteiu.,    p.    421, 

pi.  xix,  fig.  4. 
y  —        Cardium    Hillanum,   E.  Forhcs.     Traus.  Geol.  Soc,  scr.  2,  \o\.  vii,  p.  146. 
1850.  —  —A.  d'Orhiijny.     Prodr.  de  Pal,  vol.  ii.  ]..  162. 

Protocardia  Hillana,  H.B.  Geinitz.     Das  Quadersaudst.  odevKreidegeb. 

iu  Deutschlaud,  p.  1.54. 
?  1852.     Cardium  Hillanum,  F.  Riimer.     Kreidebild.  v.  Texas,  js.  49,  pi.  vi,  fig.  12. 

—  Protocardia  Hillana,    H.    G.  Bronn.      Letliaea  Geogn.,  vol.  ii,  p.  302, 

pi.  XXX,  fig.  12. 
1854.     Cardium  bifrons,    A.    E.    Eeiiss.     Kreideschicbt.    i.   d.  Ostalpen,  p.  145, 

pi.  xxviii,  fig.  19. 

—  —         Hillanum,  J.  Morrii'.     Cat.  Brit.  Foss.,  ed.  2,  p.  192. 

1863.  PuoTocARDiA  iiii,i,Ai^A,  Ii.  Dit'schev.     Zeitsehr.  d.  doutsch.  geol.  Gesellsch., 

vol.  XV,  p.  346, 

1864.  Cahdium  (Pkotucardia)  Hillana,  K.  A.  Zittel.     DieBivalv.  d.  Gosaiigeb., 

I,  p.  42  [146],  pi.  vii,  figs.  1,  2. 
1866.  —  lliiji.XNVM,  F.  J.  Pidet  and  G.  Ciiinpiche.     Terr.  Cret.  Ste.  Croix 

(Mater.  Pal.  Suisse,  ser.  4), 
pi..  268.  273. 
?   1867.  —  —        0.  Fniiit!.     Alls  d<  m  Orient,  I,  p.  91. 

—  —  —       E.  GuiJraiiijcr.     Allmiu  I'ak'oiit.  de   la   Sartlie,  p.   16, 

pi.  XX,  figs.  3,  11. 
I86a.  —  —       A.  Briait  and  F.  L.  Cornet.     Meule  de  Bracqueguies 

(Mem.  eour.  et  Mem.  des  Sav.  ctraugers,  • 
vol.  xxxiv),  p.  66,  pi.  vii,  figs.  4,  5. 
1870.     PuuTocAKDiA  HiLLANA,  F.  Uumef.     Geol.  v.  Oberschles.,  p.  334,   pi.  xxvi, 

fig.  2. 
?   lS71.     Pkotucakdium  Hillanum,  F.  Stoliczka.     Palaeoiit.  Indiea,  Cret.  Fauua  S. 

India,  vol.  iii,  pp.  209,  219,  pi.  xii, 
figs.  8 — 10,  pi.  xiii,  figs.  1 — 3. 
1873.  —  —         II.    Ii.    Geinitz.     Das    Eibthalgeb.  in  Sacbseu 

(Piilieontogr.ipbiea,     vol.     xx, 
pt.  i),  p.  230,  pi.  1,  figs.  11,12. 

—  Cardium  —         var.  moabiticum,  L.  Lariet.     Ann.   Sci.  geol., 

vol.  iii,  p.  53,  pi.  xii,  fig.  9. 

1876.  Pkotocakdia  Hillana,  D.  Brauns.     Zeitsehr.  f.   d.  gesammt.   Naturwiss., 

vol.  xlvi,  p.  266. 

1877.  Protocardium  Hillanum,  .1.  Fritach.     Stud,  im  Gebiete  der  bolim.  Kreide- 

t'crmat.,  ii,Weisseuberg.  u.Maluitz. 
SeLiieht.,  p.  112,  fig.  64. 


PROTOCARDIA.  199 

?  1878.     Protocardium  Hili,anuivt,  0.  Fraaf:.     Ans  deiii  Orient.  II  Geol.  Beobacht. 

am  Libanon,  p.  70. 
1882.     Cardium  (Protocardium)  Hillanum,  P.   de  Loriol.     Gault  Je  Cosne,  p. 

69,  pi.  Tiii,  fig.  17. 
1884.     Protocardium    Hillanum,   /.  F.   Whiteaves.     Mesoz.  Foss.  (Geol.  Surv. 

Canada),    vol.    i,    p.  228, 
pi.  XXX,  fig.  5. 
P     —        Cardium  (Protocardia)  Hillanum,   C.  E.   Hamlin.     Mem.  Mus.  Comp. 

Zool.,  vol  X,  No.  3,  p.  50. 
1893.     Protocardium  Y{ua,,\nvm,  R.  Michael.    Zeitschr.  d.deutsch.geol.Gesellsch., 

vol.  xlv,  p.  232. 

1897.  —  —         A.Fritscli.    Stud,  im  Gebietederbolim.  Kreide- 

format.,    vi,    Chlomek.  Schicht., 
p.  52. 

—  —  —         B,.   Leonhard.     Kreidef.    in    Oberscbles.    (Pal- 

OBontograpliica,  vol.  xliv),  p.  28. 

1898.  —  —         A.Fritsch.    Stud,  im  Gebieteder  bobm.  Kreide- 

format.,  iii,  Iserschicht.,  p.  98. 

1901.  Protocardia  Hillana,  F.  Slnrm.     Jabib.  d.  k.  pieussisch.  geol.   Landes- 

anst.  fiir  1900,  vol.  xxi,  p.  79. 

1902.  —  —         A.    Quaas.     Kreidebild.    in    der    libysch.    Wiiste 

(Palseontograpbica,    vol.    sxx,    2), 
p.  218,  pi.  xxiv,  fig.  18. 
1904.  —  —         B..   Fortnu.     Bull.  Instit.   Egyptien,  ser.  4,  no.  4, 

p.  331. 

—  —  —         var.  UMKWEI.ANENSIS,  R.  Etheridge,  jun.     Second 

Rep.    Geol.    Surv.    Natal    and 
Zululand,  p.  79,  pi.  i,  fig.  16. 
1906.  —  —         xdi:,  H.  Woods.     Cret.  Fauna  of  Pondolaud  (Ann. 

S.  African  Mus.,  vol.  iv),  p.  3(i7, 
pi.  xxxvii,  fig.  6. 

Deacriptiov . — Slioll  convex,  with  flattened  posterior  slope,  nenrlj-  equilateral  ; 
outline  more  or  Ic.-^s  .suli-iiuadrate,  rounded,  .*ioinetimes  ncarl}'  oval;  usually  a 
little  higher  than  long,  but  raivly  with  the  height  and  length  erpial  Anterior 
margin  eitliei-  fairly  conve.x  and  forming  a  rounded  angle  with  the  antero-dorsal 
margin,  or  very  convex  and  passing  almost  gradually  into  the  antero-dorsal 
margin.  Anterior  margin  passes  gradually  into  the  ventral  mai-gin,  which  may  be 
considerably  convex,  but  is  usually  only  slightly  convex,  with  its  posterior  part 
nearly  straight  and  forming  a  more  or  less  well-marked  angle  with  the  posterior 
margin.  The  latter  is  truncated,  slightly  convex,  and  forms  an  obtuse  angle  with 
the  postero-dorsal  margin.     Umbones  of  moderate  size. 

Ornamentation  consists  (except  on  the  posterior  part  of  the  shell)  of  junnerons, 
very  regular,  rounded,  concentric  ribs  separated  by  narrow  furrows;  these  ribs 
become  smaller  or  nearly  obsolete  near  the  antero-dorsal  margin.     On  the  posterior 


200  CRETACEOUS   LAMELLIBRANCHIA. 

slope  of  the  shell,  ;md  soiiietiuies  for  a  short  distance  in  front  of  it,  are  from  lU  to  1-j 
(usually  12  or  13)  strong,  more  or  less  angular  ribs,  separated  by  broad  furrows, 
both  being  crossed  by  well-marked  growth-ridges.  Sometimes  some  of  these  ribs 
are  divided  at  their  summits  by  a  narrow,  longitudinal  groove.  The  ribs  become 
rather  smaller  dorsally  and  are  absent  near  the  postero-dorsal  margin.  Internal 
margins  of  valves  smooth,  except  the  ])ostcrior  jiai-t  with  radial  I'ibs,  which  is 
serrate. 


easwemenfs : 

(1) 

(a) 

(:*) 

(0       (.r,)      (0)     (7)      (s) 

(9) 

(10) 

(11) 

(12) 

Length     51 

48 

44 

44     43     41     38     36 

36 

32 

27 

19  mm 

Height     47 

47 

44 

42     41     39     36     36 

(1—12)  Black-down. 

34 

29-5 

26 

18    „ 

Affinities. — Although  this  species  has  a  very  wide  geographical  distribution 
and  a  long  range  in  time,  yet  the  principal  variations  seen  in  specimens  found 
at  different  horizons  and  in  different  kinds  of  sediment  consist  in  the  number  and 
coarseness  of  the  concentric  ribs.  The  modifications  do  not  appear  to  Ijc  more 
than  varietal,  and  such  as  would  be  found  at  the  present  day  in  examples  of  a  widely 
distributed  species. 

In  the  example  from  the  Cenoraanian  figured  by  d'Orbigny  the  shell  is  i"ather 
higher  and  the  ornamentation  coarser  than  in  specimens  from  Blackdown,  but  in 
the  latter  respect  it  agrees  with  examples  found  by  the  late  C.  J.  A.  Meyer  in  the 
Cenomanian  of  Soiith  Devon.  One  specimen  from  the  Cenomanian  of  Sarthc, 
shown  in  Gueranger's  photographic  illustrations,  agrees  in  its  ornamentation  with 
Blackdown  examples. 

The  Cenomanian  form  figui'ed  by  Romer  (1870),  and  the  examples  from 
higher  horizons  figured  by  Geinitz  (1843)  and  by  Goldfuss  agree  closely  with  Black- 
down  specimens.  Coarser  ribbing  is  found  in  specimens  from  the  Gault  of  Cosne, 
showing  that  that  character  is  not  limited  to  examples  from  horizons  above  the 
Blackdown  Greensand. 

Protocar(Jia  hifrons  (Reuss)  is  more  rounded  than  P.  Ilillana,  but  does  not  seem 
to  be  specifically  distinct. 

Gdvdium  mnrticense,  Matheron,  and  ('.  llequienianum,  Matheron,  were  regarded 
by  d'Orbigny  and  by  Zittel  as  synonyms  of  P.  Ilillana. 

Specimens  from  the  Trichinopoli  Group  of  Soutliern  India  weir  identified  with 
]\  Ilillana  by  Forbes  and  by  Stoliczka,  who  stated  that  they  were  unable  to  draw 
any  line  of  separation  between  the  Indian  and  Kui-opean  examples.  Tlu>  concen- 
tric ribbing  is  coarser  in  most  of  the  Indian  forms,  and  in  some  the  smooth  inner 
portion  of  the  posterior  area  is  relatively  larger  than  in  specinuMis  from  Blackdown.' 

•  Sec  Stoliczka's  fif,'.  I0,r. 


CARDIUM.  201 

P.  dellcatula,  Stoliczka/  and  P.  pondicheriensr  (d'Orhigny),^  are  allied  to 
P.  Hillana. 

P.  hiseriatii  ((Jonrad),'^  from  Syria,  possesses  coarse  concentric  ribs,  and  is 
regarded  by  Blanckenhorn  as  a  variety  of  P.  Hillana. 

BemarlcH. — Examples  of  this  species  are  common  at  Blackdown,  but  probal)ly  on 
account  of  the  uniformity  of  the  conditions  under  wliich  they  lived,  do  not  show 
any  very  striking  variations. 

There  are  some  differences  in  the  proportion  of  length  and  height ;  usually  the 
former  exceeds  the  latter  slightly,  ])ut  occasionally  the  two  are  equal.  The  outline 
of  the  shell  is  sometimes  oval,  but  more  usually  subquadrate.  The  radial  ribs  vary 
in  number  from  10  to  15,  and  sometimes  the  area  with  these  ribs  is  continued  for  a 
short  distance  in  front  of  the  posterior  slope. 

The  number  of  concentric  ril)s  in  10  mm.  (measured  between  34  mm.  and 
44  mm.  from  the  umbo)  varies  from  15  to  19. 

Tiipe. — From  Blackdown,  in  the  British  Museum. 

Disfrihution. — Upper  Greensand  (zone  of  Schhvnhacliia.  rostrata)  of  Blackdown, 
Haldon,  Whitecliff  (South  Devon),  I'eak  Hill  near  Sidmouth,  Devizes,  and 
Ventnor.  Cenomanian  of  Dunscoinlie.  Recorded  by  .Jukes-Browne  from  the 
Chloritic  Marl  of  the  Isle  of  Wight. 

Genus — Cakdium,  f/iiui,rus. 
('Syst.  Nat.,'  ed.  10,  1758,  i..  678;  ed.  12,  17GG,  p.  1121.) 

Cardium  Ibbetsoni,  Forbes,  1845.     Plate  XXXII,  figs.  7 — 10. 

1845.     Cardiijm  Ibbetsoni,  E.  Forbes.     Quart.  Jouin.  Geol.    Soc,  vol.  i.  p.  243, 

pi.  ii,  fig.  9. 
1854.  —  —  J.  Morris.     Cat.  Brit.  Fo§s.,  ed.  2,  p.  Ut2. 

1856.  —  —  F.    J.    riiirl   and  E.   Beuevier.     Foss.   Terr.    Aptien 

(Mater.  Pal.  Suisse,  ser.  1),  p.  78, 
pi.  ix,  figs.  1,  2. 
1866.  —  —  F.  J.  Pirtel  and  G.  Campiche.     Terr.  Crct.  Ste.  Croix 

(Matc'r.  Pal.  Suisse,  ser.  4), 
p.  262. 
1871.  —  —  {ItMyicKnmvM),  F.  Stoliczka.     Pateout.  ludica,  Cret. 

Fauna  S.  India,  vol.  iii,  p.  213. 

I  'PahcDiit.  Indiea,  Cret.  Fauna  S.  India,'  vol.  iii  (1871),  ]).  220,  pi.  xiii,  fig.  8. 

-  St.diczka,  ibid.,  p.  220,  pi.  xii,  figs.  4—7. 

3  '  Official  Report  U.  S.  Exped.  Dead  Sea,  etc.,'  by  W.  F.  Lynch  (1852),  p.  216,  pi.  vi,  figs.  38,  39 
(non  40);  R.  B.  Newton,  'Geol.  Mag.,'  (1898),  p.  40t1,  jd.  xv,  fig.  11.  F.  Hillana  var.  lypica, 
M.  Blanckenhorn,  'Beitr.  zur  Geol.  Syriens  :  Kreidesyst.  in  Mittel  u.  Nord-Syrieus  '  (1890),  p.  89. 


202  CRETACEOITS   LAMELLTBRANCHTA. 

JJrsrripfinu. — Shell  siuall,  inflated,  oval,  a  little  higher  than  long,  slightly 
inecjuilateral.  Anterior  margin  rounded,  passing  gradually  into  the  convex 
ventral  margin.  Posterior  margin  sul^truncate,  higher  than  the  anterior  margin. 
UmVwnes  prominent,  with  a  faint  carina  extending  to  the  postero- ventral  extremity 
and  forming  tlu^  limit  of  the  flattened  postero-dorsal  area.  Margins  of  valves 
serrate. 

Ornamentation  consists  of  numerous  small,  slightly-raised  radial  ribs  separated 
by  narrow  grooves ;  anteriorly  the  ribs  become  gradually  smaller  and  are  absent 
or  indistinct  near  the  antei'o-dorsal  margin ;  on  the  postero-dorsal  area  the  ribs 
are  stronger  and  the  grooves  broader  than  elsewhere,  and  the  anterior  margins  of 
these  ribs  are  sometimes  serrate.  In  Avell-preserved  specimens  faint  concentric 
linear  ridges  are  seen. 

Meafnimnrvfa  : 

(1)  (2)  (3) 


(4) 

(5) 

14 

1  (>•-")  mm 

14-5      . 

11         „ 

Length     .17         .         15-5      .         14-2      . 
Height     .18         .         16-5      .         15 

(1—5)  Crackers.  AthertieUl. 

Affiuifirs.—iiec  G.  GuttaUmnm  (p.  203). 

In  form  C.  Ibbetsoni  resembles  0.  Banliniannm,  d'Orbigny,^  but  the  latter  is 
distinguished  by  its  broader  grooves  which  bear  pointed  projections.- 

In  the  specimens  figured  by  Pictet  and  Renevier  from  the  Aptian  of  the  Perte 
du  Rhone  the  umbones  are  more  prominent  than  in  English  examples  of 
0.  Ihhdsoni,  but  Pictet  and  Campiche,  who  were  able  to  compare  examples  from 
Atherfield  with  those  obtained  from  the  Perte  da  Rhone,  felt  no  doubt  as  to 
their  specific  identity. 

Ti/pe. — From  Atherfield,  iu  the  Museum  of  the  Geological  Society. 

Distribution. — Lower  Grreensand  (Crackers)  of  Atherfield. 

'  -Pill.  Frauv-  Terr.  Cn't.,'  vol.  iii  (1844j,  p.  25.  pi.  cc-xlii,  fi.i,'s.  7—11. 

'  C.  Bauliniannm  is  rocorJed  by  Morris  from  the  Lower  Greensaml  nt'  t  ln'  Isle  of  Wight,  aud  by 
Topley  from  the  Atherlield  Beds  of  Peasmarsh  and  Shalfonl.  Specimens  from  the  Atherfiehl  Clay 
wei-e  referred  to  C.  suhhUlaimm,  Leymerie,  by  Forbes,  but  that  identilication  was  regarded  as  doubtful 
by  Pictet  and  Campiche  ;  the  form  of  the  shell  cannot  be  made  out  satisfactorily,  but  the  ornamenta- 
tion resembles  that  of  G.  Ibbetsoni.  Au  internal  cast  from  the  Lower  Grreensand  of  Upware  was 
referred  with  doubt  to  C.  unhhillaitnin  by  W.  Keeping  (' Foss.  Neoc.  Upware  and  Brickhill,'  1883, 
p.  119)  ;  the  specimen  is  now  in  the  Sedgwick  Museum,  Cambridge,  and  seems  to  me  insufficient 
for  determination.  A  specimen  with  radial  ribs,  from  the  Lower  G-reensand  of  Maidstone,  was  named 
CartJium  Bemtedi  by  Forbes,  but  was  too  imi)erfect  for  figuring  ;  the  type  is  in  the  Museum  of  the 
Geological  Society  (No.  2124)  ;  no  other  specimen  has  been  seen.  Forbes,  'Quart.  Jouru.  Geol.  Soc.,' 
vol.  i  (184.5),  p.  244 ;  Pictet  and  Canii)ichc,  '  Foss.  Terr.  Cn't.  Ste.  Croix  '  ('  Mater.  I'al.  Suisse,'  ser  4, 
186G).  p.  267. 


CARDIUM.  203 


Cakuium  Cottaijunum,  (CUrbhjiuj,  J 8-14.     Plato  \XX1I,  tig.  11  a — n. 

1844.     Cakdium  CoTTALDiNUM,  A.  d' O fhlij II ij .     Pal.    Frauy.    Terr.  Civt.,   vol.   iii, 

p.  22,  pi.  cc.xlii,  figs.  1 — 4. 

1850.  —  —  d'OrhUjiiij.     Pi-odr.  de  Pal.,  vol.  ii,  p.  79. 

1866.  —  • —  /''.  /.  Pictet  and  G.  Campiche.     Terr.  Crut.  Stu. 

Croix  (Mater.  Pal.  Suisse,  ser.  4), 
p.  246,  pi.  cxviii,  figs.  1,  2. 
1871.  —  —  F.    StoUczka.     Palseont.    ludica,  Cret.  Fauna   8. 

India,  vol.  iii,  p.  212. 
1S83,  —  —  W.  Keepimj.     Foss.,  etc.,  Neoc.  Ui^ware  and  Brick- 

hill,  p.  118,  pi.  vi,  fig.  4. 
1884.  —  —  O.Weerth.    Die  Fauna  des  Neocom.  im  Teutoburg. 

Walde  (Palreout.  Abhandl.,  vol.  ii), 
p.  44,  pi.  ix,  fig.  3. 
—  —         Obrlinghusanum,  Weerth.     Ibid.,  p.  44,  pi.  ix,  fig.  4. 

1895.  —         CoTTALDiNDM,  G.  Matts.     Zeitscbr.  der  deutsch.  geol.  Gesellsch., 

vol.  xlvii,  p.  263,  pi.  vii,  figs.  2,  3. 
1900.  —  —  A.  Wollemanii.     Die  Biv.  u.  Gastrop.  d.  deutsch.  u. 

liolliiud.  Neocoms  (Abhandl.  d. 
k.  preussiseh.  geol.  Laud.,  n.  f., 
pt.  31),  p.  107. 

Descrlptidii. — Shell  oval,  inflated,  sligiitly  iiu'nuilateral,  rather  higliex"  than  long. 

Anterior  autl  ventral  margins  rounded.     Posterior  margin  more  or  less  truncated. 

Umbones  rather  high,  sharp,  curved  inward  and  forward,  with  an  indistinct  carina. 

Ornamentation  consists  of  numerous,   small,   regular,    radial   riljs,   which    are 

rather  more  proiuinent  on  the  posterior  area  than  on  the  sides  of  the  shell. 

Measurenieiifs  : 

Length         ....  24'     mm. 

Height  ....  25"5     „ 

Upware. 

Alfiiiifies. — This  species  closely  resembles  C.  Iljhctsuiil,  Ijut  iliffers  in  having  the 
posterior  area  less  flattened  and  the  outline  of  the  shell  more  rounded.  The 
English  specimens  of  G.  Cuttaldinuin  are  larger  than  those  of  G.  Ibhelsoui,  but  are 
not  sufficiently  numei'ous  oi'  well-preserved  for  exact  comparison. 

In  C.  Guttaldinum  the  shell  is  relatively  higher  than  in  (/'.  Voltzi,  Leymerie.' 

G.  laiideronense,  de  Loriol,"  appears  to  be  closely  i-elated  to  G.  Guttaldinum. 

Type. — D'Orbigny's  specimens  came  from  the  Neocomian  of  Wassy  (Ilaute- 

'  For  references  see  Pictet  and  Campiche,  '  Terr.  Crct.  Ste.  Croix '  ('  Mater.  Pal.  Suisse,'  ser.  4, 
1866).  p.  247. 

-  P.  de  Loriol  aud  V.  Gillicrou,  •  Urgouieu  luicr.  dc  Lauderou  '  (1869),  p.  14,  pi.  i,  fig.  12. 


204  CRETACEOUS   LAMELLIBRANCHIA. 

Mai'ne),    Brilloii    (Mouse),  St.    Sauveur    and    Auxerre   (Yonue).     The    specimens 
figured  hy  Keeping  are  in  the  Sedgwick  Museum. 
Distribution. — Lower  Greensand  of  Up  ware.  ^ 


Caediuji,  s]).     Plate  XXXII,  fig.  12  a,  h. 

Internal  casts  of  a  globose  form  of  (Jarduiiii  occur  in  tlie  Lower  Greensand  of 
Seend  and  Faiingdon.  On  one  specimen  (No.  21272,  Museum  of  Practical 
Geology)  a  portion  of  the  shell  is  (ii'eserved,  and  its  oi-nanientation  resembles  that 
of  G.  Ihhetsoiii  and  G.  Cottaldinuin.  The  form  of  tlie  shell  seems  to  l)e  rathei-  more 
like  that  of  (J.  llihctsonl  than  of  G.  Gotlaldiinini. 


Cabdium,  spp. 

Specimens  of  Gnrdlinu  from  the  Cenomanian  of  Dunscombe,  South  Devon,  were 
referred  by  C.  J.  A.  Meyer  to  G.  alternans,  Reuss,  and  G.  alufacemn,  Goldfuss. 
Better  preserved  specimens  are  needed  before  these  determinations  can  be  con- 
firmed. 


Cahdium  turuniknse,  WouJh,  1SV)7.     Plate  XXXII,  figs,  lo — 15. 

1897.     Cakdium  TUKoNiEN.SE,  i/.  Wooils.     Quart.  Jouiu.  Geol.  Soc,  Vol.  liii,  p.  389, 

pi.  xxvii,  figs.  20-22. 

Description. — Shell  small,  oval,  higher  than  long,  incMjuilateral,  much  inflated, 
postero-dorsal  part  compressed.  Umbones  prominent,  with  a  considerable  anterior 
curvatui'e.  Ornamentation  consists  of  many  strong  radial  ribs.  Length,  (imni.; 
height,  7  mm. 

Ajjinitles. — This  species  shows  some  resemblance  to  ('.  o'/M'/z/ffHcz/sc,  d'Orbigny,- 
but  is  more  inequilatei'al  owing  to  the  much  greater  curvature  of  the  umbones  ; 
also  the  ribs  are  less  numerous,  and  tubercles  appear  to  be  absent  from  tln^ 
grooves. 

Type. — In  the  Sedgwick  Museum,  Cambridge. 

Distribitfioii. — Chalk  Rock  of  Cuckhamsley. 

1  Some  small  specimens  found  iu  the  Ferruginous  Sands  of  Slianklin  may  perhaps  be  referred  to 
C.  CollahUnnm,  but  they  are  too  imperfeelly  preserved  for  exact  determination. 
-  'Pal.  Frauy.  Terr.  CrJt.,'  vol.  iii  (1844),  p.  37,  pi.  ecxiix,  figs.  5—9. 


CARDIUM.  205 

Oardium,  sp.     Plate  XXXII,  fig.  IG  a,  b. 

1897.     Cardium,  sp.  cf.  cenomanense,  H.  Wooih.     Quart.  Joiini.  Geol.  Soc-.,  vol. 

liii,  p.  38i),  pi.  xxvii,  tigs.  23,  24. 

Intoi'nal  casts,  similar  in  form  to  G.  cenomanense,  d'Orbigiiy,  are  found  in  the 
Chalk  Rock  of  Cuckhamsley.  A  part  of  the  shell  is  imperfectly  preserved  on  one 
specimen  and  is  ornamented  with  fine  radial  ribs.  A  cast  measures  :  height,  8  mm.; 
length,  8  mm.;  thickness,  7"5  mm. 


Caudium,  sp.     Plate  XXXII,  fig.  17  a—c. 

Two  internal  casts  from  the  Chalk  of  Norwich  (one  of  which  was  found  by  the 
late  T.  G.  Bayfield)  are  in  the  British  Museum  (Nos.  L  19443,  L20lUo).  The  shell 
is  much  inflated,  so  that  the  height  and  thickness  are  approximately  etjual ;  the 
height  is  considerably  greater  than  the  length.  The  unibones  are  prominent. 
The  postero-dorsal  part  of  the  shell  is  flattened  and  shows  indications  of  fine  radial 
ribs. 

This  species  shows  some  resemblance  to  G.  venivlcusain,  d'Orbigny,'  but  is 
relatively  higher. 

Stili-ijcuiis — Gkanucakuium,  ir.  .1/.  (Iiilili,  18G9. 
("  Geul.  Survey  Calit'uruiii,"  '  I'aliuout.,'  vol.  ii,  p.  20G.) 

* 

Caedium  (Geanocaruium)  I'KdiJusciDEUM,  Soiverbij,  1817.     Plate  XXXII,  figs.  18,  19; 

PlateXXXIII,figs.  1  — 3. 

181G.     Cakuita  tuhkkculata,  J.  Sowcrby.     Miu.  Coiuli.,  vol.  ii,  i>.  1(7,  pi.  u.\liii. 

(Non  Cardium  tuhercuhiinm,  Liunaus). 
1817.     Cardium  pkoboscideum,  J.  Smrerbi/.     Min.  Couch.,  vol.  ii,  p.  127,  ])1.  clvi, 

%•  1- 
1835.  —       Gentian UM,  J.  i/e  C  «'5'((»'«/&y.     Ibid.  (Systematical  ludex),  vol.  vi, 

p.  242. 
1854.  —       PBOBOSCIDEUM,  /.  Morris.     Cat.  Brit.  Foss.,  eJ.  2,  p.  193. 

—  —       Gentianum,  Morria.     ibid.,  p.  192. 

1866.  -        PROBOSCIDEUM,  /•'.  ./.  Pirti't  and  G.  Catnpiche.      Foss.   Terr.   Crt't. 

Ste.  Croix  (Mater.  Pal.  Suisse, 
ser.  4),  p.  269. 

1  G.  ventricosum  is  recorded  from  the  Upper  Greensand  (zone  of  Pecten  asper)  of  Lulworth  by 

Barrois  ('Terr.  Cit't.  Super,  de  rAuglotrrre  et  de  I'ln-laiulc,'    187<;.  ji.  02).      I  have  not  .seen   any 
English  example  of  tliat  species. 

27 


2UG  CHKTACEUU8    LAMEI;L1BRA^XM1IA. 

I80(j.     CaIvUIUM  CJentianum,  Pldd  and  Camplche.     iliid.,  p.  2G9. 
1871.  —       PEOBOSCIDEUM,  F.  StoUczka.     Palseont.    ludica,    Grot.    FLUiiia    S. 

India,  vol.   iii,  p.  213   {Acatdho- 
cardinm). 
—  —       Gentianum,  StoUczJca.     Ibid.,  p.  213  {Acanthocardium). 

1882.  —       PEouosciDEUM,  P.  de  Loriul,  Gault  de  Cosue,  p.  91,  pi.  xi,  tig.  4. 

1900.  —       Gentianum,  E.  T.  Newton  and  A.  J.  Jukes-Browne.     lu  Jukes- 

Bi'owue,  Cret.  Rocks  of  Britain, 
vol.  i,  p.  448. 

Descrijifhin. — Sliell  stout,  very  convex,  ovul,  higher  than  long,  slightly  inequi- 
lateral. Anterior  margin  rounded  ;  posterior  margin  truncated,  forming  an 
angle  with  the  po.stero-dorsal  margin.     Unil)ones  prominent. 

Ornamentation  consists  of  radial  ribs  separated  Ij}-  narro^Y  grooves ;  the 
stronger  ribs  bear  prominent,  angular,  laterally  compressed  tooth-like  ))rojections, 
which  may  be  rather  larger  near  the  posterior  margin  than  elsewhere ;  in  the 
spaces  between  the  stronger  ribs  are  two  (sometimes  one  or  three)  smaller  ribs  with 
similar  but  smaller  tooth-like  projections.     Margins  of  valves  toothed. 

Measurements : 

(1)  (2)  (3) 

Length     G3         .  59         .  58 

Height      74         .         7*t         .         68 

(1—5)  Blackdowu. 

Affinities. — A  form  from  the  Cenomanian  was  referred  l)y  d'Orbigny  to 
C.  pwdnrtum,  Sowerby,^  the  type  of  which  comes  from  the  Senonian  of  Gosau. 
Tliis  identification  has  been  accepted  by  Zittel,  Holzapfel  and  others,  but  not  by 
Pictet  and  Campiche,  and  de  Loriol.  The  specimen  figured  by  d'Orbigny  -  is 
probably  an  example  of  G.  fvohoscideum,  Sowerby,  and  differs  from  G.  prothidum 
in  the  distinct  differentiation  of  the  ribs  into  a  larger  series  separated  by  smaller 
series. 

The  differences  between  G.  Gentiamun  and  C.  prohosc'ideum  seem  to  be  due 
entirely  to  their  different  modes  of  preservation.  The  former  is  found  in  the 
Upper  Greensand  of  Devizes  and  Ventnor;  the  shell  is  absent,  but  the  sand  whicli 
filled  the  interior  of  the  shell  now  forms  a  natural  cast  of  the  exterior,  showing 
more  or  less  imperfectly  the  character  of  the  ornamentation  ;  usually  the  spines 
are  represented  l)y  stumps  only  or  are  almost  completely  obliterated.  In  these 
specimens  the  original  form  of  the   shell   has    been    more    or    less    considerably 

•  'Trans.  Geol.  Soc.,'  ser.  2,  vol.  iii  (1832),  p.  417,  pi.  xxxix,  fig.  15  ;  Goldfuss,  *  Petref.  Germ.,' 
vol.  ii  (1837),  p.  221,  pi.  cxliv,  fig.  7  ;  Zittel,  '  Bivalv.  d.  Gosaugeb.,'  pt.  i  (1864),  j).  37,  pi.  vi,  fig.  1 ; 
Holzapfel,  "Die  Mollusk.  Aachen.  Kreide  "  (' Palaeontographica,'  vol.  xxxv),p.  179,  pi.  xvii,  figs.  1 — 5; 
G.  Miillcr,  'Mollusk.  d.  Uutersen.  v.  Braunscliweig  u.  Ilsede  '  (1898),  p.  (33,  pi.  ix,  figs.  13,  14. 

-  '  Pal.  Frany.  Ti'rr.  Cret.,'  vol.  iii  (1844),  p.  31,  pi  i-cxlvii ;  Gucranger,  '  Album  Pak'ont.  du  la 
Sarlhe  '  (1867),  p.  15,  pi.  xx,  tigs.  8—10. 


(4) 

(5) 

57 

47  mm 

65 

54    „ 

TOUCASIA.  207 

modifitMl  l)y  pressure.  On  tlie  otlici-  hand  flic  slicll  in  C.  proboKciilniui,  from 
Blackdown,  is  replaced  by  siliea,  so  that  both  its  oniaiiiciifation  and  ori^-innl  shape 
are  perfectly  preserved. 

French  examples  were  idontitied  by  tl'Orbigny  '  with  this  species,  for  which  he 
proposed  the  name  Canliam  Moufonianvm  since  the  specific  name  (tuberculafn) 
under  which  Sowerby  originally  described  the  species  had  already  been  used. 
Sowerby,  however,  in  the  index  at  the  end  of  vol.  vi  of  the  'Mineral  Conchology,' 
had  already  substituted  Gentianum  for  the  name  which  he  originally  used.  I  have 
not  seen  an}'  specimen  of  C.  Motitoninnmn,  and  am  unable  to  say  whether  or  not  it 
is  really  identical  with  G.  Gcntlnnnm,  but  in  d'Orbigny's  figures  the  difference  in 
the  sizes  of  the  ribs  and  tubercles  is  seen  on  the  anterior  and  posterior  parts  of 
the  shell  only. 

G.  GaroUnvm,  d'Orbigny,^  and  G.incequicostatnm,  Matheron,^  are  closely  related 
to,  and  perhaps  identical  with,  G.  pnihoscidpnm. 

T;/i>cs. — G.  j)rohoscidet(,m,  from  the  Upper  Greensand  of  Blackdown,  and 
Garditii  tnhcrcuJata  (Gardium  Gentianum),  from  the  Upper  Greensand  of  Devizes, 
are  in  the  British  Museum. 

DiMrihntlon. — Upper  Greensand  (zone  of  Schlnmhachia  rosfrata)  of  Blackdown, 
Haldon,  Devizes,  and  Ventnor. 


Famihj—BlCE'RkTl'DJE,  Thill. 
Genus — ToDCASiA,  E.  Munior-Ghulmnft,  1873. 

(' Jonm.  (le  Concliyl.,'  ser.  3,  vol.  xxi,  p.  74.     Douville,  '  Bull.  Soc.  gc'ol.  de  France,'  ser.  .3,  vol.  xv, 

1887,  p.  762.) 


ToucASiA  LoNSDALEi  {Sowevhy),  183G.     Plate  XXXIII,  figs.   [■ — G. 

1836.     DiCKRAS  LoNSDALii,  .7.  (le  C.  Soiverhy.     Trans.  Geol.  Soc,  ser.  2,  vol.  iv, 

pp.  268,  338,  pi.  xiii,  fii?.  4. 
1850.     Capeotina    Lonsdalii,    A.    d'Orhitjinj.      ProJr.    de  Pal.,  vol.    ii,    p.    109 

(parti  III). 

1854.  Diceeas  Lonsdalii,  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  201. 

1855.  Requienia    Lonsdalei,    S.    P.    Woodward.      Quart.    Jouru.    Geol.    Soc., 

vol.  xi,  p.  53,  fig.  29. 
1871.  —  Lonsdai.ii,    F.    Stoliczt:a.       Palseont.    ludica,    Cret.    Fauna 

S.  India,  vol.  iii,  p.  233. 

»  '  Pal.  Fran9.  Terr.  Cret.,'  vol.  iii  (1844),  p.  34,  pi.  ccxlviii ;  and  '  Prodr.  de  Pal.,'  vol.  ii  (1850), 
p.  162. 

-  Op.  cit.  (1844),  p.  29,  pi.  fcxlv. 

*  '  Catal.  Foss.  des  Boucli.'s-du-Rlione  '  (1842),  y.  157,  pi.  xviii,  figs.  3,  4. 


208  CRETACEOUS   LAMELLIBRANCHTA. 

Bemarks. — The  examjiles  of  Toucasia  Lonsdalei  are  m  the  condition  of  internal 
casts  in  a  ferruginous  sandstone,  so  that  it  is  difficult  to  compare  this  with  other 
species.  The  casts  show  a  considerable  amount  of  variation  in  form.  D'Orbigny, 
de  Loriol,  and  Pictet  and  Campiche  included  Bcquienia  carinata,  Matheron,'  from 
the  Urgonian  of  Orgon,  as  a  sj'nonym  of  Sowerby's  DIceras  Lonsdalei;  but  Prof. 
Douville-  and  M.  Paquier^  think  that  the  identity  of  the  two  forms  is  doubtful 
and  can  only  be  determined  by  a  careful  comparison  of  English  specimens  witli 
internal  casts  of  T.  cnrinnta.  Prof.  Douville  *^  suggests  that  there  is  a  resemblance 
between  T.  Seunesi  and  T.  Lonsdalei. 

Type. — The  type,  which  is  stated  to  have  come  from  near  Calne,  cannot  now 
be  found.  The  specimen  from  which  Woodward's  outline  figure  was  drawn  is  in 
the  British  Museum,  No.  88825. 

DlstriliKtion. — Lower  Greensaud  of  Stock  Orchard,  south  of  Calne.  Recorded 
by  Morris  from  Lockswell  Heath,  south-west  of  Calne. 


Famil ij— MO^OFhFAmiBJE,  Fischer. 
Genus — Gyropleura,  7/.  Ihnirdl',  1887. 

('Bull.  Soc.  gt'ol.  (le  France,'  ser.  3,  vol.  xv,  p.  7()8.) 


GYRorLEUifA  coRNUCopi.K  {d'Orhiijii //),  1847.     Plate  XXXIII,  fig.  7  a,  Ik 

1847.     Chama  coRNUoopiiE,  A.  J'Orhujny.     Pal.  Fniuc.  Terr.  Cret.,  vol.  iii,  p.  689, 

pi.  cecclxiv,  figs.  3 — 7. 
18r,0.  —  —  tl'Orhicjny.     Prodr.  (le  Pal,  vol.  ii,  p.  170. 

1 808.         —  —  F.  J.  Pictet  and  G.  Campiche.    Terr.  Crut.  do  Ste.  Croix 

(Mati'r.  Pal.  Suisse,  ser.  5),  p.  7. 
1871.         —  —  F.  Htoliczlca.     Paloeout.  ludica,  Cret.  Faima  S.  India, 

vol.  iii,  p.  234. 
1887.     Gyropleura  —  //.  Douville.     Bull.  Soc.  jjfrol.  de  France,  ser.  3,  vol. 

XV,  p.  771,  fig.  3. 

Bemnvls. — ^^vo  s]K'ciniens  rroui  llic  Clilorit  ic  i\I;ii'l  of  Dorset  agree  in  i'onu 
with  e.\aiuj)le.<i   of   (!.  cornucoina.'  from    tlie   Cenomanian  of    Houen   (the  locality 

1  '  Catal.  Foss.  des  Bouclics-du-Ilhoiie'  (1842).  p.  U)4,  pi.  ii,  figs.  1,2;  Cajirotina  Lonsdalii, 
d'Orbiguy,  '  Auu.  Sci.  Nat.  Zool.,'  ser.  2,  vol.  xvii  (1842),  j).  180;  liecpiienia  Lonsdalii,  d'Orbiguv, 
'Pal.  Franc.  Terr.  Crot.,'  vol.  iv  (18.50),  p.  248,  pis.  dlxxvi,  dlxxvii ;  Caprvlinn  Lonsdalii,  de  Loriol,  in 
Favrc,  '  Rcch.  gi'ol.  dans  Savoio,'  vol.  i  (18()7),  p.  38(i,  pi.  C,  fig.  22;  licfjuicnla  Ldn.^dalii,  Pictot  and 
Campiche,  'Terr.  Cri't.  Ste.  Croix'  ('Mater.  Pal.  Suisse,'  ser.  5,  1868).  p.  14,  pi.  clxi. 

2  'Bull.  Soc.  gcol.  de  Franco,'  ser.  3,  vol.  xvii  (188!»),  p.  630. 

^  'Les  Rudistcs  Urgouieus,'  I  ('  Mrin.  Soc.  gi'ol.  de  France,'  i'aK'out.  XI,  11)03),  p.  41. 
*  Op.  cit.,  p.  632. 


GYROPLEURA.  209 

of  the  type)  and  with  d'Orbigny's  figs.  4  and  5.  The  ornamentation  in  this 
species  is  imperfectly  known ;  most  of  the  examples  from  Ronen  are  either 
internal  casts  or  have  only  portions  of  the  shell  present,  on  which  the  orna- 
mentation is  rather  indistinct.  In  one  specimen  from  Dorset  part  of  the  shell 
of  the  fixed  valve  is  preserved ;  the  radial  ribs  are  not  so  prominent  as  in 
Ct.  ivpijiiiroKh-iifd,  ])ut  concentric  lamellte  are  distinct. 

Distribiifinn. — Chloritic  Marl  of  Melbury  Park  and  Chaldon,  Dorset.  Recorded 
by  Jnkes-Browne  from  the  base  of  the  Lower  Chalk  of  C'liard  and  Maiden 
Newton. 


GYRorLEURA  INEQUIROSTRATA  {Wondivard),  1 880.     Plate  XXXIII,  figs.  8 — 13. 

1833.     DiCERAS  iNEQUiRosTRATus,  S.  Wondivard.    Geol.  Norfolk,  p.  47,  pi.  v,  fig.  22. 
1854.     Chama  in.«quirostrata,  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  194. 

Description. — Shell  nmch  inflated.  Right  valve  large,  oval,  attached  by  a 
considerable  portion  of  the  anterior  side;  nmho  prominent,  pointed,  incurved 
anteriorly.      Left  valve  capuliform,  with  the  umbo  near  the  hinge-margin. 

Ornamentation  consists  of  strong,  lamellar  radial  ribs,  which  are  undulose 
where  they  cross  growth-i'ings.  The  ribs  have  strongly  serrate  summits  and 
are  separated  by  rather  broad,  flat,  smooth  interspaces ;  sometimes  the  serrations 
are  replaced  by  iininerons  transverse,  scale-like  structures.  Near  the  fixed  part 
of  the  ri<j;ht  valve  the  ribs  are  more  numerous  than  on  the  flank. 

Measirremeids  of  fixed  value.  : 

(1)  (2) 

Length       .         .     22         .  ID 

Height       .  .28         .         2(5 

(1 — 4)  Norwich. 
AJfinifie!<. — G.  rijili/aiia  (dc  Ryckholt),'  from  Ciply,  differs  from  this  species 
in  having  the  ribs  more  widely  separated  and  in  the  presence  of  small  ribs  in 
the  inter.spaces  and  on  the  sides  of  the  main  ribs.  CI.  rn.'isiensi.v  (d'Orbigny)- 
i-eseml)les  closely  G.  ineqnirostrata  and  was  regarded  by  Morris  as  a  synonym  of 
the  hittei-,  but  it  possesses  small  ribs  on  the  sides  of  the  main  ribs.^ 

1  '  Mi'laii-es  Tak-uut.,"  pt.  ii  (18.51),  p.  179,  pi.  xii,  %s.  12,  13;  Douvilk',  'Bull.  Soc.  gc'ol.  de 
Fniuce,'  ser.  3,  vol.  xv  (1887),  p.  744,  pi.  xxviii,  fig.  11 ;  Holzapfel, '  Mollusk.  Aachen.  Kreide '  (1889), 
p.  189,  pi.  xix,  figs.  5,  6;  Wollemanu,  '  Fauua  d.  Liiuelmrg.  Kreide'  (1902),  p.  75,  pi.  ii,  figs.  5,  6. 

-  Murehisou,  de  Vernciiil,  and  de  Keyserliug,  '  Gcol.  do  la  Kussie,'  vol.  ii  (1845),  p.  49(j,  pi.  xliii, 
figs.  31—33  ;  Douvilk',  'Bull.  Soc.  gc'ol.  de  France,'  ser.  iii,  vol.  xv  (1887),  p.  775,  pi.  xxviii,  fig.  13. 

»  G.  Miinsteri  (v.  Hagenow)  is  probably  related  to  O.  hmqmrontrala.  See  Kavii,  '  MoUuslc.  i 
Daniuarlis  Kr.-idtafl.  I.  Laiiullibr.'  (1902).  p.  12(5,  pi.  iv,  figs.  10,  11. 


(3) 

(4) 

16 

14  mm. 

20 

18     „ 

210  CRETACEOUS   LAMELLIBRANCITIA. 

Type.— From  Norwich;   in  tiie  Jiritish  Museum. 

Distrihution. — Upper  C-lialk  (zone  of  Iklemnitdla  mucronalu)  of  Norwich. 


GvKoi'i.KTUA,  sp.     Plate  XXXIV,  fig.  1  a — d. 

Ih'xcri plioii. —  Iiiti'ht  valve  inflated,  attnehcd  \)\  a  lar^'e  poi'tioii  of  the  dorsal 
surface.  Left  valve  convex,  subcjuadrate,  with  a  ])ointed  tind  incni'ved  und)o. 
Rinht  valve  ornamented  with  numerous,  small  radial  ril)s  which  bear  transverse 
nodes  or  scales.  Left  valve  with  relatively  few,  stout  ribs  bearing  strong,  some- 
what irregular,  transver.so  scales  or  lappet-like  projections. 

AJfinifM's. — The  ornamentation  on  the  right  valve  is  finer  and  that  on  the  left 
valve  coarser  than  in  G.cenomannisis  (d'Orljigny ')  ;  also  the  t  ransverse  ornamenta- 
tion of  the  ribs  is  much  coarser  and  less  regular.- 

Bemarkti. — The  portion  of  the  right  valve  which  was  attached  includes  the 
umbo  and  the  neighbouring  parts,  whereas  in  most  examples  of  Oyroplenra  only 
the  part  in  front  of  the  umbo  is  attached.  The  size  of  the  area  which  was  attached 
is  larger  than  usual,  but  in  other  s]iocies  it  is  seen  that  that  area  varies  consideral)ly 
in  size  in  different  examples.^ 

The  only  specimen  seen  was  collected  liy  Mr.  Francis  R.  B.  Williams. 

Disti-il)iifin]i. — LTpper  Chalk  (zone  of  Actinocamax  quadra Iiik)  near  the  groyne 
at  Seaford. 


F«.miZ?/— CORBULID^,  Fleming. 

Genus — CoRUULA,  /.  G.  Ihnguiire,  1707. 
('  Encyc.  Mt'tb.,'  Tabl.  Vers.,  pi.  230.) 


Cnnnt'LA  ANOur.ATA  (rhillip^),  1820.     Blate  XXXIV,  figs.  2—5. 

1829.     IsocARDiA  ANGULATA,  J.  Phillipn.     Gcol.  Yorks.,  p.  94,  pi.  ii,  fiiis.  20,  21 

(ed.  3,  1875,  p.  252). 
1841.  —  _         p.  ^.  Burner.       Die      Versteiu.     d.     uord  -  deutsch. 

Kreidegeb.,  p.  70. 
1854.  —  —J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  204. 


1  '  Pal.  Fraiu;,  Terr.  Cn't.,'  vol.  iv  (1850),  p.  261,  pi.  dxcv,  fiii;s.  1—4. 

2  Douvilk',  'Bull.  Soc.  grol.  do  France,'  ser.  3,  vol.  xv  (1887).  p.  771,  pi.  xxviii,  fit;.  7. 

■''  In  a  specimen  figured  by  Griepeukerl  tbe  surface  of  attacbmeut  is  unusually  large ;  '  Senon  v. 
Kimigsluttor '  ('Palseont.  Abliaudl.,'  v,  1889),  pi.  vii,  fig.  3. 


CORBULA.  211 

18t)5.     IsooAKUiA?  ANUULATA,  F.J.  Pictt't  and  G.  Cuinpiche.    Foss.  Terr.  Crct.  Ste. 

Croix  (Mater.  Pal.  Suisse, 
ser.  4),  p.  240. 
1871.     IsocARDiA  ANGULATA,  F.  Staliczku.     PaloGout.  luJica,  Cret.  Fauua  S.  luclia, 

vol.  iii,  p.  194. 
1877.     IsocARDiA  ?  ANGULATA,  &'.  iy'////)(.      Zeitsclir.    d.  deutscli.    geol.    Gesellscb., 

vol.  .xxix,  p.  241. 
1889.     IsocAKDiA  ANGULATA,  G.  W.  LampliKjli.     Quart.  Jo\u-u.  Geol.  Soc,  vol.  xlv, 

p.  616. 
1900.  —  —  A.  WoUemann.     Die  Biv.  u.  Gastrop.  d.  deutscli.  u. 

bolliiud.  Neocoms  (Abliaudl.  d.  k. 
preussiscli.  geol.  Laud.,  N.  P.,  pt. 
31),  p.  114. 

1905.  CoKBULA  (Isocardia)  AviovhAiA,  E.  Harhort.    Fauua  d.  Seliaiunberg-Lippe- 

scbeu  Kreidemulde  (Ibid., 
pt.  45),  p.  81. 

1906.  Isocardia  angulata,  A.  WoUemann.     Die  Biv.  u.  Gastrop.  nord-deutsch. 

Gaults  (Jabrb.  d.  k.  preussiscb. 
geol.  Laud.,  filr  1906,  vol.  xxvii), 
p.  277. 

Descrijjtioii. — Shell  witli  8ul)-(]uadrate  outline,  rounded,  occasionally  sub- 
triangular,  very  convex,  equivalve,  more  or  less  considerably  inequilateral ;  length 
greater  than  height.  Anterior  part  produced,  rounded ;  ventral  margin  slightly 
curved ;  posterior  margin  truncate,  slightly  convex,  somewhat  oblique,  forming 
angles  with  the  ventral  and  dorsal  margins.  Postero-dorsal  margin  sloping 
ventrally.  Umbones  moderately  large,  curved  inward  and  more  or  less  considerably 
forward,  with  a  carina  extending  to  the  postero-ventral  angle,  cutting  off  a  large, 
flattened  postero-dor.sal  area.  The  part  of  the  valve  in  front  uf  the  carina  is 
regularly  convex.     Lunular  region  depressed. 

Ornamentation  consists  of  fine  concentric  striae. 
Measarctiioits : 

(3)  (-4) 

6-2     .     G 
5-0     .     5 

(1 — 7)  Speetou. 

Ajjiiiitii'.-i. — This  species  shows  some  resemblance  to  C.  tjatilliiui  (see  p.  21  1),  but 
is  more  nearly  (juadrate  in  outline,  relatively  longer,  of  larger  size,  and  without 
distinct  ribs. 

G.  aiKjulata  is  fairly  common  in  the  Speeton  Clay,  but  no  specimen  showing  the 
hinge  appears  to  have  l)een  found,  so  that  the  generic  position  assigned  to  this 
species  by  Phillips  was  presumal)ly  based  on  the  external  character  of  the  shell. 
Pictet  and  Campiche  thought  that  it  probably  belonged  to  Ci/jn-iiui.  WoUemann 
states  that  it  is   most  likely  a  Curiula,  and   Harbort,  who  has  seen   the  hinge, 


(1) 

(^) 

Length 

.     7-1     . 

,     G-8 

Height 

.      G-U 

5'5 

(■') 

(fi) 

(7) 

G-0     . 

.     5-U 

.     4"5  mm 

4-.-> 

.     4-1 

.      1-0     „ 

212  CRETACEOUS    LAMELLIBRANCHIA. 

(U'fiiiitely  refers  it  to  that  genus;  if  this  view  of  its  position  is  confirmed  it  will  be 
necessary  to  substitute  a  new  name,  since  angulata  had  been  previously  used  by 
Lamarck  for  a  species  of  Gorhnla  from  the  Eocene. 

Distribufdun. — Speeton  Clay  {'/.ones  oi  Belemnites  jaculu in  and   //.  hnnisviceims) 
of  Speeton.^ 


CoKiJULA  STIUATULA,  S(jwcrhi/,  182/.      I'kite  XXXIV,  tigs.  G — 12. 

1827.      COBBULA   STKIATULA,  J.  dv  C.  Suivcvbij.      Mm.    Cuucli.,    Vol.    vi,    p.    loi',    pi. 

dlxxii,  figs.  2,  3. 
1846.  —  —A.  d'OrUynij.     P;il.  Fniuv-  Ti-rr.  Crt't.,  vol.  iii,  p.  459, 

pi.  ccflxx.wiii,  figs.  9 — 13. 
1850.  —  —  A.  d'Orhhjny.     Prodr.  do  Pal.,  vol.  ii,  p.  ILS. 

1854.  —  —  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  190. 

1868.  —  —  F.  J.PidelundE.  Kcnevier.  Toss.  Terr.  Aptieu  (Mater. 

Pal.  Suisse,  ser.  1),  p.  17(J. 
18(34.  —  —  F.  J.  Piclet  and  G.  Camjiiche.     Foss.  Terr.  C'rct.  Ste. 

Croix  (Mati.'r.  Pal.  Suisse,  ser.  4), 
p.  86. 
1870.  —  —  F.  Stoliczka.     Palseout.  ludica,  Cret.  Fauua  S.  ludia, 

vol.  iii,  J).  40. 
1895.  —  —  •  G.  Maas.     Zeitschr.  der  deutscli.  geol.  Gesellscb.,  vol. 

xlvii,  p.  257. 
—  —         Ldivis,  Maas.     Ibid.,  p.  257. 

1900.  —         STRiATULA,  A.  Wollemaun.     Die  Biv.   u.  Crastrop.  d.  deutscli.  u. 

holliiud.  Neocoms  (Abhaudl.  d.  k. 
preussisch.  geol.  Laud.,  N.  F.,  pt. 
31),  p.  144. 

Nou  1840.  —  —  A.  Goldfuss.     Petref.  Germ.,  vol.  ii,p.251,  pi.  eli,  fig.  16 

{C.  siihsl  rial  Ida,  d'Orbigny,  1850). 

—  1847.  —  —J.  Miillcr.     Petref.  der  AacLen.  Kreidel'.,  pt.  i,  p.  25, 

pi.  ii,  fig.  8. 

—  1854.  —  —  A.  d'ArcJduc.     Bull.  Soc.  geol.  de  France,  ser.  2,  vol.  xi, 

p.  209,  pi.  iv,  figs.  14,  15. 

—  1858.  —  —  J.  Vilanova-y-Piera.     Mem.  geog.-agric.  de  Castellou, 

pi.  iii,  fig.  14. 

—  1867.  —  —  0.  Fraas.     Aus  dcm  Orient,  p.  92. 

—  1870.  —  —  H.  Credner.     Zeitschr.  der  deutscli.   geol.   GesellscJi., 

vol.  xxii,  p.  236. 

1  The  type  of  Corhida  pvncfjim,  Phillips,  from  Speeton,  cannot  be  found,  and  I  have  not  seen  any 
specimen  which  could  be  satisfactorily  ideutitied  with  that  species.  Phillips, '  Geol.  Yorks.'  (1829). 
p.  122,  pi.  ii,  fig.  6. 


CORBULA.  213 

Nou  1885.     C0BBULAMEH.A  sTRiATULA,  /.  BiJim.     Verhaudl.  d.  uat.  Vereiues  d.  preuss. 

Rheinl.,  vol.  xlii,  p.  144. 

—  1887.  —  —  F.  Freeh.     ZeitscLr.  d.  deutscli.  geol.  Gesellsch., 

vol.  xxxix,  p.  173,  pi.  xii,  figs.  5—8. 

—  1888.  —  —  G.  Midler.     Jahrl).  d.  k.  preussiscli.  geol.  Laud., 

fiir  1887,  p.  436. 

—  -     1889.     CoRBULA  STRIATULA,  0.  Oriepenkerl.      Senou.    v.    KiJuigslutter    (Palseont. 

Abliandl.,  vol.  iv),  p.  69. 

—  1897.  —  —A.  Frih-ch.     Stud,    im    Gebiete    der    bohm.    Kreide- 

format.,  vi,  Cliloinek.   Schicht.,  p.   64, 
fig.  83. 

—  1901.     CoEBULAMELLA  STEiATUi.A,  F.  Stumi.     Jalirb.  d.  k.  prenssisch.  geol.  Land., 

fih-  1900,  vol.  xxi,  p.  88. 

Description. — Shell  ovate,  usually  mucli  inflated,  produced  and  pointed 
posteriori)',  inequilateral,  slightly  inequivalve.  Anterior  and  ventral  margins 
rounded.  Posterior  margin  short,  obliquely  truncated.  Umbones  l)road,  strongly 
incurved,  with  a  carina  extending  to  the  postero-ventral  angle  and  cutting  off 
a  flattened  postero-dorsal  area.  Ornamentation  consists  of  numerous  concentric 
ribs  which  extend  on  to  the  postero-dorsal  area,  where  they  are  narrower  and  more 
distinct. 

Measurements  : 

(1)  (-')  (3) 

Length  .  6"7  .  6*0  .  5"5  mm. 

Height  .  5-0  .  4-2  .  4-0    „ 

(1)  Atherfield  Beds,  East  Shalford ;  (2,  3)  Crackers,  Atherfield. 

Affinities. — This  species  is  distinguished  from  C.  neocomiensi,^,  d'Orbignj-,^  by 
the  smaller  and  more  pointed  posterior  end.  It  differs  from  G.  suhstriatula  in  being 
less  inequivalve  and  in  possessing  a  distinct  carina.  WoUemann  considers  that 
C.  Isevis,  Maas,  is  identical  with  C.  striatala.  Another  form  which  appears  to  be 
closely  allied  is  G.  neverisensis,  de  Loriol,-  from  the  Gault  of  Cosne. 

Remarks. — This  species  varies  considerably  in  convexity  and  in  relative  length 
and  height.  The  shorter,  more  globose,  and  more  distinctly  rostrate  forms  agree 
with  the  type.  The  more  elongate  and  less  convex  forms  are  not  so  numerous, 
and  although  differing  considerably  in  shape  from  the  globose  forms,  yet  they 
agree  with  them  in  other  respects  and  do  not  appear  to  be  specifically  distinct. 

Specimens  from  the  Lower  Greensand  of  Punfield  resemble  G.  striatula,  but 
possess  stronger  concentric  ribs — in  some  cases,  as  in  the  example  figured  (Plate 
XXXIV,  fig.  13),  the  ribs  are  consideral)ly  stronger,  but  in  others  the  difference 


IS  not  so  great. 


1  'Pal.  Fraue.  Terr.  Crct.,'  vol.  iii  (1846),  p.  457,  pi.  ccclxxxviii,  figs.  3 — 5,  and  '  Prodr.  de  Pal.,' 
vol.  ii  (1850),  p.  76. 

'-  •  Gault  de  Cosne'  (1882),  p.  43,  pi.  v,  figs.  23—25. 

28 


214  CRETACEOUS   LAMELLIBRANCHIA. 

T^ipe. — Internal  casts  from  the  Hytlie  Beds  of  Pulborouo-h,  in  tlie  British 
Museum. 

Distribution . — Lower  Greensand  :  Crackers  of  Atherfield.  Recorded  by  Fitton 
from  the  Penia-bed,  Atherfield  Clay,  and  Beds  VI— IX,  XIII,  XIV  near  Atherfield. 
Ferruginous  Sands  of  Shanklin.  Atherfield  Beds  of  Peasmarsh,  East  Shalford 
and  Sevenoaks.     Hythe  Beds  of  Pulborough.     Folkestone  Beds  of  Folkestone. 


CoRBULA  GADiiTiNA,  Pictet  and  Campiche,  1864.     Plate  XXXIV,  figs.  14 — 16. 

1864.     CoEBUL.\.  GAULTINA,  F.  J.  Pictet  and  G.  Campiche.     Foss.  Terr.  Cret.  Ste. 

Croix  (Mater.  Pal.  Suisse,  ser.  4), 
p.  34,  pi.  c,  figs.  3,  4. 

1870.  —  —  F.  Stolkzka.     Palaeont.  Indica,  Cret.  Fauna  S.  ludia, 

vol.  iii,  p.  40. 

Description. — Shell  subtriangular,  rounded,  inflated,  slightly  inequivalve,  a 
little  longer  than  high,  moderately  inequilateral.  Anterior  margin  rounded. 
Posterior  margin  subtruncate,  oblique.  Umbones  prominent,  rather  high,  curved 
forward,  with  an  inconspicuous  carina  cutting  off  a  concave  postero-dorsal  area. 
Ornamentation  consists  of  small,  concentric  ribs. 

Measurements  : 

(1)  (2)  (3)  (1) 

Length  5*5         .  O'O         .         4-6         .  4-0  mm. 

Height        .         5-0         .         4-5         .         4-0         .         3-6     ., 

(1 — 1)  Gaiilt,  Folkestone. 

Affinities. — In  this  species  the  shell  is  relatively  shorter  and  more  inflated  than 
in  G.  elegantida,  d'Orbigny.' 

C.  riaidtiua  may  perhaps  be,  as  was  pointed  out  by  Pictet  and  Campiche, 
identical  with  G.  socialis,  d'Orbigny,^  of  which  no  sufficient  diagnosis  has  been 
given. 

Bemarl-s. — Numerous  individuals  of  this  species  are  found  close  together  in 
groups.  When  the  surface  of  the  shell  is  not  perfectly  preserved  the  ribs  liecome 
indistinct. 

Tijpe. — From  the  Gault  of  Folkestone. 

Distribution. — Lower  Gault  (Bed  2)  of  Folkestone. 

1  'Pal.  Fran?.  Terr.  Cret.,'  vol.  iii  (1846),  p.  460,  pi.  ceclxxxviii,  fi-s.  U— 17. 
3  'Prodr.  de  Pal.,'  vol.  ii  (1850),  p.  136. 


CORBULA.  215 


CoRBUiA  TBUNCATA,  Sowerbij,  1836.     Plate  XXXIV,  figs.  17 — 22. 

1836.     CoRBULA  TBUNCATA,  /.  de  0.  Soiverhij.     Trans.  Geol.  Soc,  ser.  2,  vol.  iv, 

pp.  240,  341,  pi.  xvi,  fig.  8. 
1850.  —  —A.  d'Orbigny.     Prodr.  de  Pal,  vol.  ii,  p.  160. 

1854.  —  —  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  196. 

1868.  —  —  A.  Briart  and  F.  L.  Cornet.     Meule  de  Braequegnies 

(Mem.  cour.  et  Mem.  des  Sav.  etraugers,  vol.  xxxiv), 
p.  81,  pi.  vi,  figs.  13 — 15. 
1870.  —  —  F.  Stoliczka.     Palseont.  Indica,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  40. 
(?)  1895.  —        cf.  —  E.    Tieasen.      Zeitschr.    d.   deutsch.    geol.    Gesellsch., 

vol.  xlvii,  p.  485. 

Non  1846.  —  —  A.  d'Orbigny.     Pal.  Fran9.  Terr.  Cret.,  vol.  iii,  p.  461, 

pi.    ccclxxxviii,    figs.    18 — 20    (?  C. 
Goldfitssiana,  Matheron). 

Description. — Shell  subquadrate  or  subtriangular,  elongate,  rounded,  moderately 
convex,  inequilateral,  slightly  inequivalve,  considerably  longer  than  high.  Anterior 
margin  well  rounded.  Ventral  margin  slightly  convex,  its  posterior  part  bending 
upwards.  Posterior  margin  obliquely  truncated,  forming  an  acute  angle  with  the 
ventral  mai'gin  and  an  obtuse  angle  with  the  dorsal  margin.  Umbones  broad, 
with  a  carina  extending  to  the  postero-ventral  angle  and  cutting  off  a  flattened  or 
concave  postero-dorsal  area.  Ornamentation  consists  of  numerous  fine,  concentric^ 
ribs  which  are  continued  on  to  the  postero-dorsal  area. 

Measurements  : 

(1)  (2)  (3)  (4) 

Length   ...         9  8*5  8  7'5  mm. 

Height    .         .         .         6*5  6  5'75  5       „ 

(1 — 4)  Blackdowu. 

Affinities. — This  species  is  less  elongate  than  C.  trnncata,  d'Orbigny,  and  is 
also  distinguished  by  its  concentric  ornamentation.  It  differs  from  C.  lineata, 
Miiller,^  in  the  greater  obliquity  of  the  posterior  margin  and  in  the  more  numerous 
concentric  ribs. 

Tijije. — From  Blackdown,  in  the  Bri.stol  Museiun. 

Distribution. — Upper  Greensand  (zone  of  Schlivubachia  rostrata)  of  Blackdown. 

'  Holzapfel,  "Die  Mollusk.  Aachen.  Kreide  "  ('  Palseontographica,'  vol.  xxxv,  1889),  p.  146,  pi.  x, 
figs.  16—19. 


216  CRETACEOUS   LAMELLIBRANCHIA. 

CoRBULA  ELEGANS,  Sowerhy,  1827.     Plate  XXXIV,  figs.  23 — 28. 

1827.     CoRBULA  ELEGANS,  /.  ih'  C.  Soirerhi/.    Mill.  Coiicli.,  Vol.  vi,  p.  130,  pi.  (llxxii, 

fi^-  1- 
1850.  —  —A.  d'Orhiijny.     Prodr.  de  Pal.,  vol.  ii,  p.  160. 

1854  —  —         J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  195. 

?  1867.  —  —         ?,  E.  Gic'ranger.     Album  Pali-out.  de  la  Sarthe,  p.  12, 

pi.  xvi,  fig.  1. 
1870.  —  —         F.  Stoliczka.      Palaeont.  Indica,  Cret.   Fauiia  S.   ludia, 

vol.  iii,  p.  40. 

Non  1846.  —  —A.  d'Orhujny.     Pal.  Fraiic.  Terr.  Cret.,  vol.  iii,  p.  460, 

pi.  ccclxxxviii,  figs.  14 — 17  (C.  elegantnla,  d'Orbigny, 
1850). 

?  —  1847.  —  — •        ?,  A.  d'Archiac.     Mem.  Soc.  geol.  de  France,  ser.  2, 

vol.  ii,  p.  302. 

Description. — Shell  subtrigonal,  rounded,  very  convex,  inequivalve,  inequi- 
lateral, a  little  longer  than  high. 

Right  valve  with  the  anterior  ]iart  sloping  rapidly  to  the  margin ;  anterior 
margin  rounded;  ventral  margin  convex,  its  posterior  part  curving  upwards. 
Posterior  part  produced,  compressed,  separated  from  the  sides  by  a  groove  passing 
from  the  umbo  to  the  postero-ventral  angle ;  on  the  dorsal  side  of  the  groove  is  a 
small  carina.  Posterior  margin  truncated,  forming  approximately  a  right  angle 
with  the  straight  postero-dorsal  margin.  Umbo  prominent,  sharp,  curved  con- 
siderably inward  and  somewhat  forward.  Ornamentation  consists  of  strong, 
broad,  concentric  ribs  separated  by  narrow  grooves,  except  on  the  postero-dorsal 
area,  which  is  nearly  smooth. 

Left  valve  smaller,  less  convex,  and  with  smaller  ribs  than  the  right  valve. 
Postero-dorsal  area  separated  from  the  side  of  the  valve  by  a  groove  or  sharp 
carina. 

Measurements  : 

(1)  (2)  (3)  (4) 

Length     ...  (3  5'5  5  4"5  nun. 

Height     .         .         .         475  4-5  4  3-G    „ 

(1 — 4)  Blackdowu. 

Affinities. — This  species  is  distinguished  from  G.  elegantnla,  d'Orbigny,  l)y  its 
broader  concentric  ribs  and  rostrate  posterior  end.  It  is  less  globose,  less  pointed 
posteriorly,  and  has  stronger  ribs  than  C.  suhstrintitla ,  d'Orliigny. 

Type. — From  Blackdowu,  in  the  British  Museum. 

Distribution. — Upper  Greensand  (zone  of  Schlcenbachia  rostra  fa)  of  Blackdowu 
and  Hal  don.  Recorded  l^y  Price  from  the  Upper  and  Lower  Gault  of 
Folkestone. 


iPaLxontoovaphical  Soctct\>,   1000. 


A     M  O  N  O  CI  R  A  P  H 


CRETACEOUS    LAMELLIBIUNCHIA 


ENGLAND. 


HENRY  WOODS,  M.A. 

UNIVERSITY    LECTUKEK    IN    PAL.E0Z00L08T,    CAUBUIDQE. 


VOL.  IL     PART  VI. 

SOLENID^,  SAXICAVID.E,  PHOLADID.E,  TEREDINID.E,  ANATINIDiE, 
PHOLADOMYID/E,    PLEUROMYID.E,    POROMYACIDyE,    AND 

CUSPIDARIID^. 

PAaES  217—260;  Plates  XXXV— XLIV. 


L  0  N  D  ()  N  : 
PRINTED     FOR     THE     P  AL  .EONTOG  R  A  P  H  I  C  A  L     SOCIETY. 

1909. 


PKINTEI)    BV    ADLAUU    ANU    SON,    LONDON    AND    DORKINO. 


PHARUS.  217 


F^^/«%— SOLENID.E,  Lnmarrh. 

Gemis — Pharus,  Lench  in  J.  7?.  Grni/,  1847. 

('  Syuops.  Brit.  Mas.,'  e<l  42,  1840,  p.  154 ;  '  Anu.  Mag.  Nat.  Hist.,'  vol.  xx,  1847,  p.  272  ; 

and  '  Proe.  Zool.  Soc.,'  1847,  p.  189.) 

Pharus  Waeburtoni  (Forhes),  184.3.     Plate  XXXV,  figs.  ]— 3. 

1845.     SoLECUETUs  Warbtjrtoni,  E.   Foi-hes.     Quart.   Journ.  G-eol.  Soc,  vol.    i, 

p.  237,  pi.  ii,  fig.  1. 
1850.  —  —A.  (VOrbigny.     Prodr.  de  Pal.,  vol.  ii,  p.  117. 

1854.  —  —  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  224. 

1864.  —  —  F.  J.  Pidet  and    G.    Campiche.      Foss.   Terr. 

Crct.  Ste.  Croix  (Mati'r.  Pal. 
Suisse,  ser.  4),  p.  30. 
1870.  —  —  F.  StoliczJm.     Palaeout,  ludica,  Cret.  Fauna  S. 

India,  vol.  iii,  p.  99. 

Description. — Shell  elongate-oblong,  compressed,  slightly  inequilateral,  gaping 
at  the  ends,  the  posterior  higher  than  the  anterior  part.  Dorsal  margin 
almost  straight.  Ventral  margin  slightly  flexnous,  and  shghtly  oblique  to  the 
dorsal  margin.  Anterior  margin  rounded.  Posterior  margin  slightly  truncate, 
rounded.  Umbones  small,  inconspicuous,  sulj-median.  Ornamentation  consists  of 
growth-rings,  and  on  the  anterior  part  of  the  shell,  of  numerous,  very  small,  rather 
irregular,  radial  ribs. 
Measurements  : 

(1)  (2)  (3)  (i) 

Length     .     67         .         60-5      .  55         .         44-  mm. 

Height     .17         .         IG         .         15         .         12     „ 

(1^-4)  Crackers,  Atherfield. 
Affinities. — This  species,  as  was  pointed  out  by  Stoliczka,  closely  reseml)les  in 
foi-ni  living  examples  of  the  genus  Pharus ;  but  the  hinge  appears  to  be  miknown, 
for  although  the  species  is  well  represented  in  collections,  and  the  specimens  are 
in  an  excellent  state  of  preservation,  none  of  them  sliows  the  interior  of  the  shell. 
A  single  valve  resembling  P.  Warburtoni,  but  relatively  higher,  has  been  described 
by  Dr.  Kitchin'  from  the  Uitenhage  Series.  Dr.  Harborf-  states  that  his  Solecurtus 
lungovatas  is  similar  to  our  species,  but  is  relatively  higher  and  sliorter. 

1  *  Ann.  S.  African  Mus,,'  vol.  vii  (1908).  p.  155,  fij,'.  1. 

=  'Die  Fauna  d.  Sdiaumburg-Lippe'schen  Kreidemuldc '  (1905),  p.  71,  pi.  viii,  fig.  6.  Au 
imperfect  internal  cast  found  in  the  Upper  Greeusand  of  Devizes  shows  some  i-esemblauce  to  this 
species. 

29 


218  CKETACEOUS    LAMELLIBRANCHIA. 

Tijpe. — From  Atlierfiekl,  in  the  Mu«euin  of  the  Geological  Society. 
Distribution. — Lower  Greensaud  (Crackers)  of  Atlierfiekl.      Atherfiekl  Beds  of 
East  Shalford  and  Sevenoaks.     Sandgate  Beds  of  Parham  Park. 


Genus — Solecuhti's,  //.  M.  J),  df  llhn'nrilk',  1824. 

('Diet.  Sc'i.  luit.,'  viil.  x-xxii,  p.  3-51.) 

Stih-f/enus — Azoii,  11^.  E.  Latch,  1847. 

(In  Gray,  '  Ann.  Mag.  Nat.  Hist.,'  vol.  xx,  p.  '272  ;  and  '  Proc.  Zool.  Soc.,'  1847,  p.  189.) 

SoLECDRTUS  (AzoK  r)  PEi,.\Gr,  iVOrhii/in/,  1 8")0.     Plate  XXXV,  fig.  4. 

1850.     SoLECURTUs  Pelagi,  a.  d'Orhiijnij.     Prodr.  de  Pal.,  vol.  ii,  p.  1.58. 

1867.  —  —       E.  Gurromjer.     Album  Pak'ont.  de  la  Sarthe,  p.  12, 

pi.  XV,  fig.  6. 
1870.  —  —        F.  StoJiczha.     Palseont.  Indica,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  99. 

Descrij)tion. — Shell  elongate,  considerably  inequilateral,  moderately  convex,  but 
slightly  concave  at  the  middle  of  the  sides.  Postero-dorsal  area  flattened  or  slightly 
concave,  limited  by  an  indistinct  carina.  Antero-dorsal  margin  cui-ved ;  anterior 
margin  rounded;  postero-dorsal  margin  straight,  nearly  j^arallel  to  the  ventral 
margin;  posterior  margin  curved,  slightly  oblique.  Ornamentation  consists  of 
small  concentric  ribs  near  the  umbo,  and  of  growth-rings  elsewhere.  Length  :?0 
mm. ;  height  12  mm. 

Ajjiuities. — The  identification  of  the  English  specimens  with  tl'Orbigny's  species 
is  not  quite  free  from  doubt,  since  only  two  valves,  both  somewhat  imperfect,  have 
yet  been  seen.  In  the  specimen  figured  by  Gueranger  the  postei'o-dorsal  area 
seems  relatively  higher  than  in  our  si)eciiHens ;  also  the  postero-dorsal  margin  is 
less  nearly  straight,  but  this  difference  may  be  due  to  imperfect  preservation. 

S.  Pelagi  seems  to  be  closely  allied  to  S.  Guc.ra>if/erl,  d'Orbigny,'  but  the 
carina  is  less  distinct,  and  the  postero-ventral  angle  appears  to  be  more  rounded. 

Until  specimens  showing  the  hinge  satisfactorily  have  been  found,  the  generic 
position  of  this  species  must  be  regarded  as  doubtful. 

Ti/pe. — From  the  Cenomanian  of  Le  Mans. 

Distribution. — L^pper  Greensand  (zone  of  SclihrnlKicJiin  ruatrdtn)  of  Blackdown. 

^  'Pal.  Frany.  Terr.  Crt't.,'  vol.  iii  (1845),  p.  321,  pi.  cccli,  figs.  1,  2.  Gut'ranger,  'AUnun 
Pak'ont.  de  la  Sarthe'  (1867),  p.  12,  pi.  xv,  fig.  4.  An  inturual  cast  of  a  left  valve  from  the  Upper 
Gi'eensaud  of  Warminster  resembles  S.  Guerangeri. 


LEPTOSOLEN.  219 


SoT.ECUKTus?  (Azoii?)  AcTEOx,  iVOrhhjmj,  1850.     Plate  XXXV,  figs.  5,  G. 

1850.     SoLECURTUs  AcTEON,  A.  d'Orhiijiiy.     Prodr.  cle  Pal.,  vol.  ii,  p.  158. 

1867.  —  —       E.  Giii'ranyer.     Album  Pak'out.  de  la  Sarthe,  p.  12, 

pi.  XV,  figs.  1,  2. 
1870.  —  —       F.  Stoliczha.    Palseont.  ludica,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  99. 

Description. — Shell  somewhat  oblong,  moderately  inequilateral,  moderately 
conve.x,  witli  flattened  sides  and  flattened  postero-dorsal  area.  Anterior  margin 
rounded  ;  postero-dorsal  margin  nearly  straight,  sloping  ventrally  fi'om  the  umbo; 
posterior  margin  slightly  convex,  somewhat  oblique  ;  ventral  margin  nearly  parallel 
to  the  dorsal  margin  and  forming  a  rounded  angle  with  the  posterior  margin. 
Umbones  broad,  inconspicuous.  Ornamentation  consists  of  strong,  regular,  con- 
centric ribs,  separated  by  furrows  of  greater  breadth. 

Measurements  (approxhaatc)  ; 

(1)  (2) 

Length  .  .  .  46         .         20  mm. 

Height  .  .  .  24         .  10     „ 

(1)  Haldou,  (2)  Dunscombe. 
Affi)dties. — Only    two    specimens    have    been     seen ;    they    resemble    closely 
Cxueranger's  figures  of   -S'.  Adeon.     The  hinge  is  unknown,  so  that  the  generic 
position  cannot  be  determined  at  present. 
Type. — From  the  Cenomanian  of  Le  Mans. 

Distribution. — Upper  Greensand  (zone  of  ScJdd-iiIinrhia  rostnita)  of  Haldon. 
Cenomanian  (]\Ieyer's  Bed  10)  of  Dunscombe,  South  Devon. ^ 

G'ejnf.s'^LEiTOSor.EN,  T.  A.  Conrad,  1867. 

('Amer.  Jouru.  Couch..'  vol.  iii,  pp.  15,  188  ;  F.  B.  Meek,  'Invert.  Cret.  and  Tert.  Foss. 

U.  Missouri,'  1876,  p.  252.) 

Leptosolen  Dupixr.ANUs  (d'Orhiijuij),  1845.     Plate  XXXV,  figs.  7,  8. 

18-15.     SoLEN  DupiNiANUS,  A.  (V Oihlij)) I/.     Pal.  Frauc.  Terr.  Cret.,  vol.  iii,  p.  320, 

pi.  cccl,  figs.  3,  4. 
1850.         —  —  A.  d'Orbi(jny.     Prodr.  de  Pal.,  vol.  ii,  p.  135. 


1  An  internal  cast  from  the  Ceuomauiau  (Bed  11)  of  Dunscombe,  South  Devon,  resembles 
Soleciirtiif  !i'(ii(a}is,  d'Orbigny,  l>ut  is  not  sufTuientlv  well-preserved  for  ideutificatiou.  S.  /cqiialig  has 
been  referred  doubtfully  to  the  genus  rharrlln  by  Stoliczka  and  by  Meek,  whilst  de  Loriol  regards  it 
as  belonging  to  Siliquaria  (=  Tagahig).  See  d'OrV)igny.  'Pal.  Fi-au?.  Terr.  Cret.,'  vol.  iii  (1845), 
p.  321,  pi.  cccl,  figs.  5—7,  and  'Prodr.  de  Pal.,'  vol.  ii  (1850),  p.  158;  Gueranger,  '  Allmm 
Paleout.  de  la  Sarthe  '  (1867),  p.  12.  pi.  xv,  fig.  3. 


220  CRETACEOUS    LAiMELLIBRANCHIA. 

1864.     SoLEN  DUPiNiANUs,  F.  J.  Ficfii  and  G.  Caiiipiche.     Terr.  Cret.  Ste.  Croix 

(Mati'r.  Pal.  Suisse,  ser.  4),  p.  29. 

1897.         —  —  R.  B.  Neivtoii.     Proc.  Dorset   Nat.  Hist,  aud  Antiq. 

Field  Club,  vol.  xviii,  p.  93. 

Description. — Shell  ulongate,  more  or  le.ss  oblong,  slightly  convex,  coinpre.ssed 
near  the  antero-dorsal  margin,  considerably  inequilateral.  Dorsal  margin  nearly 
straight.  Anterior  end  roimded,  not  so  high  as  the  posterior  part  of  the  shell. 
Ventral  niai'gin  nearly  straight  and  neai'ly  pai'allel  to  the  dtirsal  margin,  curving 
upAvards  anteriorly.  Posterior  margin  convex,  forming  a  rounded  angle  with  the 
ventral  margin.  Umbones  small,  inconspicuous,  situated  at  less  than  a  third  of 
the  length  of  the  shell  from  the  anterior  margin. 

Ornamentation  consists  of  small  concentric  ridges;  in  some  cases  the  ridges 

cut  the    ])osterior  part    of   the  ventral  margin  obliquely.     A  strong  internal   rib 

extends  from  the  umbo  veutrally,  l)ut  does  not   reach  the  venti-al  mai'giii. 

Measurements : 

W  (2)  (a) 

Length        .  .  31         .         29         .         2G  mm. 

Height        .  .  10         .         10         .  9     „ 

(1—3)  Gault,  Black  Veu. 

AQiniticfy. — The  occurrence  of  this  species  in  the  Gault  of  England  has  been 
recorded  by  De  Ranee  and  R.  B.  Newton — by  the  former  from  Black  Ven,  and  by 
the  latter  from  Okeford  Fitzpaine.  Although  the  example  figured  by  d'Orbigny 
is  imperfect,  consisting  of  the  posterior  part  of  a  left  valve  only,  yet  the  English 
specimens  agree  sufficiently  closely  with  d'Orbigny's  figure  to  make  it  probable 
that  they  have  been  correctly  identified  with  fj.  Diqnnianus.  In  most  of  the 
English  examples,  however,  the  posterior  margin  is  more  convex  and  the  ])ostero- 
dorsal  angle  more  rounded  than  in  d'Orbigny's  figure;  but  in  a  few  s^jeciniens, 
which  have  been  slightly  crushed,  these  differences  are  not  noticeable. 

The  species  which  resemble  L.  JJiqnniaiiKS  are  A/.  ro)u-riitrisfriiihi!>  (Miiller'), 
L.  Petersl  (Reuss"),  /;.  fnnicuhila  (Reuss'^),  L.  ]\liire<tna  (d'Orbigny')  and  /,.  liimita 
(Stoliczka"'). 

Ti/pc. — From  the  Albian  of  Ervy  (Aube). 

JJlstrlhution. — Lower  Gault  of  Black  Yen  antl  Okeford  Fitz|)aine.  L'lqier  Green- 
sand  of  Devizes.     Recorded  by  Jukes-Browne  from  the  Gault  of  the  Isle  of  Wight. 

'   '  Jalirli.  d.  k.  preussiseh.  i,'e(il.  Laudesanst.  i'iir  1887  '  (1888),  p.  4ol,  pi.  xviii.  fii,'.  5. 

'  '  Kreidesc-bicht.  i.  d.  Ostalpeu '  (1854),  p.  145,  pi.  xxviii,  fiy.  lO.  Zittel.  "Die  Bivalv.  d. 
Gosaugeb.,'  I  (1865),  p.  5  [109],  pi.  i,  fi;;-.  3. 

^  '  Die  Versteiu.  derbiibm.  Kreidei'i)rinat.,'  \t\.  '1  (1846),  p.  17,  pi.  xxxvi.  fi,L;.s.  13,  16,  17. 

»  'Pal.  Fraiu;.  Terr.  Crut.,'  vol.  iii  (1845),  p.  324,  pi.  eecl,  figs.  8—10.  Tins  species  bas  beeu 
recorded  by  Barrois  from  tbe  Upper  Greensand  of  Lulwortb  and  Devi/es  ;  I  bavi;  not  seen  any 
examples  from  tbosu  localities. 

"•>  'Palseout.  Indica,  Cret.  Fauna  S.  India'  (1870).  p.  101,  pi.  i,  tigs.  12,  13. 


PANOPEA. 


221 


Faurih/— iiAXlCAY ID JE,  Gnnj. 

Geiuis — Panoi'EA,  Mthiard  df  la  <!rtiijc,  18U7. 
(' Auu.  Mus.  Hist,  uat.,  Paris,'  vol.  ix,  p.  lol,  pi.  xii.j 

Panopea,  sp.     Text-fig.  27. 

Internal  casts  of  a  larg-e,  convex  riumj^iea  occur  in  the  Tealby  Limestone  of 


.7 


7/ 


■'^' 


Fia.  •J.'.  —  I'iinopea,  s\>.     IValliy  Limestone,  North   \\'illiu;^haiii,  Lincolnsliiiv.     Sedgwick  Jluseuin,  Camln-idiji'.    x  |. 

Hainton,  Claxliy,  and  North  \\'iIliiiL;Iiani,  Llncdlnsliire.  In  foi'in  tliey  resemble 
some  varieties  of  /'.  (jiinjifis,  but  tlie  posterior  part  of  the  shell  is  more  elongated. 
One  specimen  shows  a  hirge  external  ligament,  and  on  a  small  portion  of  shell 
indications  of  radial  rows  of  fine  granules  are  seen.  The  pallial  sinus  is  large  and 
rounded. 


222  CRETACEOUS  LAMELLIBRANCHIA. 

Pamu'Ka  .spilsiukxsis,  sp.  iiov.     Plate  XXXVIII,  fig.  2a,h. 

Descrijjtion. — Shell  elongate-oval,  convex,  not  very  ineciuilateral.  Posterioi" 
part  more  compressed  and  not  so  high  as  the  median  and  anterior  parts.  Anterior 
margin  rounded;  ventral  margin  slightly  cnrved,  not  ([uite  parallel  to  the  long 
dorsal  margin.  Umbones  broad,  incnived,  at  about  six-fifteenths  of  the  entire 
length  from  the  anterior  end.  Pallial  sinus  large,  deep,  and  rounded.  Surface  of 
shell  nearly  smooth. 

licnuiJ'kti. — Only  a  few  internal  casts  with  small  portions  of  the  shell  preserved 
have  been  obtained,  but  they  seem  to  differ  considerably  from  other  species  and 
are  provisionally  referred  to  the'  genus  I'aiinpea. 

Distribiifioii. — Spilsby  Sandstone  (zone  of  Belemnites  lutrralb)  of  Donnington. 


Paxopea  GUKKiTis  {Brunyidaii),  1822.     Plate  XXXV,  figs.  9—U;  Plate  XXXVI, 

figs.  1—8. 

1822.  LuTRARiA  GVRGniii,  A.  Briiiniiiiart,  in  Ciivier.     Ossemeus  Foss.,  vol.  ii.pt.  2, 

pp.  333,  61.5,  pi.  ix,  fig.  15. 

1823.  Mya  plicata,  J.  de  C.  Sowerhy.     Min.  Conch.,  vol.  v,  p.  20,  pi.  ccccxix.fig.  3. 
183-5.     Panop.ea  plicata,  Soirerbi/.     Ibid.,  vol.  vi,  Systeiuat.  Index,  p.  2-11. 

1841.  —  —         F.    A.    Rijmev.         Die    Verstein.     d.    nord  -  deutscli. 

Kreidegeb.,  p.  75,  pi.  ix,  fig.  25. 

1842.  Phiiladomya  neocomiensis,  A.  Leymerie.    Mcni.  Soc.  gt'ol.  de  France,  ser.  2, 

vol.  V,  p.  3,  pi.  iii,  fig.  4. 

—  —  Prevosti,  Beshayesf  in  Leymeri-;.     Ibid.,  p.  3,  pi.  ii,  fig.  7. 
1845.     Panop.ba  neocomiensis,    A.  d'Oiiiiijny.     Pal.   Fraiic.   Terr.  Cret.,  vol.  iii, 

ji.  329,  pi.  cccliii,  figs.  3—8. 

—  —  Pkevosti,  d'Orhnjny.     Ibid.,  p.  334,  pi.  ccclvi,  figs.  3,  4. 

—  NEOCOMIENSIS,  £.  jFor6e».     Quart.  Joui  ii.  Geol.  Soc,  vol.  i,  p.  288. 

—  —  PLICATA,  Forbes.     Ibid.,  p.  238. 

—  Mtopsis  NEOCOMIENSIS,  L.  ^(/n««('2.     Jltudes  crlt.  Moll.  Foss.,  M\es,  p.  257, 

pi.  xxxi,  figs.  5 — 10. 

—  —         UNioiDES,  Aijassiz.     Ibid.,  p.  258,  pi.  xxxi.  figs.  11,  12. 

1850.     Panop.ea  NEOCOMIENSIS,  A.  d'Orhiijny.     Prodi',  de  Pal.,  vol.  ii,  pp.  73,  117. 

—  —         Prevo.stii,  d'Oi-hiijiiy.     Ibid.,  pp.  105,  117. 

1852.  —         plicata,  F.  J.  Pirti't  and  W.  Koux.      Moll.   Foss.  Grcs  verts  de 

Geneve,  p.  399,  pi.  xxviii,  fig.  2. 

—  —         Khodani,  Fictt'l  and  Muiix.     Ibid.,  p.  400,  pi.  xxviii,  tig.  3. 

1854.  MvAciTES  NEOCOMIENSIS,  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  213. 

1855.  Panop.«a  —  F.  J.  Pictet  and  E.  Renevler.     Foss.  Terr.  Aptieu 

(Mati'r.  Pal.  Suisse,  ser.  1),  pp.  56,  175,  pi.  vi, 
figs.  2,  3. 

—  —  plicata,  Ficfet  and  Renevier.     Ibid.,  p.  .')7,  pi.  vi.  figs.  4,  5. 


PANOPEA.  223 

1855.     Panop^a  neocomiensis,  G.  Cofteau.     Moll.  Foss.  de  rYoime,  p.  51. 

1861.  —  —  P.  de  Loriol.     Auim.  Invert.  Foss.  Mt.   Salcve, 

p.  55. 

1864-5.        —  —  F.J.Plctei  (vid  G.CampicJie.  Foss.  Terr.  Civt.  Ste. 

Croix  (Mater.  Pal.  Suisse,  ser.  4), 
p.  49,  pi.  c,  figs.  10—12. 

1865.  —         PLICATA,  Pictet  and  Campiche.     Ibid.,  p.  63. 

1869.  —         NEOCOMIENSIS,  P.  de  Loriol  and  V.  Gilli'-roii.     Urgoii.   infer,   de 

Lauderou,  p.  lH,  pi.  i,  fig.  10. 

1870.  —  —  F.  StoHczka.     Palseont.  Indica,   Cret.    Fauna   S. 

India,  vol.   iii,  p.  87. 
1877.  —         PUNCTATO-PLICATA,  6r.  !?"/(//(.  Zeitschr.  d.  deutscli.  geol.  Gesellscli., 

vol.  xxix,  p.  241. 
?  1883.  —         PLICATA,  W.  Keeping.     Foss.,  etc.,  Neoc.  Upware  and  BriL-kliill, 

p.  126. 
1884.  —         NEOCOMIENSIS,  O.Weertli.    Die  Fauna des  Neoeom.  iniTeutuburg. 

Walde  (Palaeont.  Abhandl.,  vol.  ii), 
p.  37,  pi.  viii,  fig.  7. 
1886.     Pleuromya         —  H.  Trautschold.     Ncocom.  de  Sably  (Nouv.  Mi'ni. 

Soc.  Impi'r.  Nat.  Moscou,  vol.  xv),  p.  135. 
1892.     Panop.s:a  —  O.Behrendsen.  Zeitsehr.d.deutseh.geol.Gesellsch., 

vol.  xliv,  p.  20. 

1895.  —  —  G.  Maas.     Ibid.,  vol.  xlvii,  p.  256. 

—  —  —  F.  Voijel.     HoUiiudiscli.  Kreide,  p.  59. 

1896.  —  —  A.WoUemann.   Zeitscbr.d.  deutscli.geol.Gesellscli., 

vol.  xlviii,  p.  849. 

1897.  Pleuromya  plicata,  R.  B.  Newton.     Proe.  Dorset  Nat.  Hist,  and  Antiq. 

Field  Club,  vol.  xviii,  pp.  71,  93, 
pi.  ii,  figs.  4,  5. 

1898.  —  NEOCOMIENSIS,  E.  G.  Sheat  and  V.  Madsen.     Jur.   Neoc.  autl 

Gault  Boulders  in  Denmark  (Danmarks  geol. 

Uudersog.,  2  K.,  Nr.  8j,  p.  185,  pi.  vi.fig.  11. 

1900.     Panop^a  —  A.WoUemann.    Die  Biv.  u.  Gastrop.  d.  deutsch. 

u.  bolliiud.  Neoconis  (Abhandl.  d.  k. 
preussisch.  geol.  Laud.,  N.  F.,  pt.  31), 
p.  124. 

1905.  —  —  E.  Harhort.     Die  Fauna  d.  Schaumburg-Lippe- 

'schen   Kreideniulde   (ibid.,  pt. 
45),  p.  74. 

1906.  —  —  A.    WoUemann.       Jalirb.    tl.    k.    preuss.    geol. 

Landesaust.  fiir  1906,  vol. 
xxvii,  p.  278. 
1908.  —  —  A.  Stojanoff.     Ann.  gi'ol.  et  miu.  de  la  Eussie. 

vol.  X,  p.  115. 

Non  1827.     Lutearia  guroitis,  S.  Nilsson.     Petrif.  Suecaua,  p.  18,  pi.  v,  fig.  9  (Ghjci- 

meris  Hohap/eli,  Henuig). 
—   1837.  —  —         W.  Hisinijer.     Lethsea  Suecica,  p.  67,  pi.  xx,  fig.  1. 


224  CRETACEOUS   LAMELLIBRANCHIA. 

Nou  1840.     Panop^a  gcrgites,  A.  Golclfiiss.     Petref.  Germ.,  vol.  ii,   p.  274-.  pi.  iliii, 

fig.    7     (P.     G'oldfiisei,    d'Orbigny, 
1850). 

—  —  —         PLicATA,  Gohlj'iisn.     Ibiil.,  p.  274,  pi.  olviii,  fiyj.  5. 

—  1845.  —         G0RG1TIS,  A.  d'Orbigny.     Pal.  Fraiu;.  Terr.  Crt't.,  vol.  iii,  p.  345, 

pi.  ccclxi,  fiys.  1,  2. 

—  1846.  —  —         A.  E.  Ueass.     Die  Versteiu.  der  bijluu.  Kreideforiiuit., 

pt.  2,  p.  17,  pi.  XXX vi,  fig.  3. 

—  1847.  —         PLICATA,  /,  Mailer.     Petref.    der  Aachen.  Kreidef.,  pt.   1,  p.   28 

{Glycliiieris  Gehiitzl,  Holzapfel). 

—  1873.  —         GTJEGiTis,  H.  B.  Geinitz.     Das  Elbtluilgeb.  iu  Sachsen  (Palaeouto- 

grapbica,  vol.  xx,  pt.  2),  p.  (58,  pi.  xix, 
figs.  1,  2. 

—  1876.  —  —         D.  Braiiiin.     Zeitselir.  f.   d.  gesammt.  Naturvviss.,  vol. 

slvi,  p.  362. 

—  1877.  ■ —  —         A.  Fritsch.     Stud,  im  Gebiete  der  bohni.  Kreideformat., 

ii,  Weissenberg.   ii.   Maluitz.    Scliicliten, 
p.  125,  fig.  100. 

—  1898.     Glycimeris    —         G.  Miiller.     Die   Mollusk.    d.    Uuterseuou   v.    Braim- 

selnveig  u.  Ilsede,  p.  70,  pi.  x,  fig.  4. 

—  1901.     Panop/EA         —         F.  Sturm.     Jalirb.  d.  k.  preuss    geol.  Landesanst.  fiir 

1900,  vol.  xxi,  p.  70,  pi.  X,  fit;.  4. 

Description. — Shell  more  or  less  oblong,  rounded,  convex;  posterior  part 
somewhat  compressed,  anterior  part  sloping  more  or  less  rapidly  to  the  margin ; 
moderately  or  considerably  inequilateral ;  i)Osterior  gape  large.  Anterior  margin 
more  or  less  convex,  sometimes  subtrimcate ;  antero-ventral  margin  rounded; 
ventral  margin  slightly  or  moderately  convex,  nearly  parallel  to  the  dorsal  margin  ; 
posterior  margin  convex,  or  subtrnncate  and  rounded ;  postero-dorsal  margin 
nearly  straight.  Umbones  incurved,  often  broad,  sometimes  narrow  and  pointed  ; 
the  dorsal  part  of  the  shell  in  front  of  the  umbones  is  moderately  or  considerably 
depressed ;  sometimes  a  more  or  less  distinct  carina  extends  from  the  umbo 
towards  the  antero-ventral  extremity ;  another  carina,  usually  faint,  may  extend 
from  the  umbo  posteriorly.     Pallial  sinus  large,  rounded. 

Ornamentation  consists  of  concentric  folds,  wliicli  may  l)c  conspicuous  or  only 
faintly  indicated,  and  of  nunicrons  radial  rows  of   minute  granules. 

Measuremeiifs  : 

(3)  (4)  (5)  (.1) 

G9     .     65     .     01     .     5(5 
:]G     .     88     .     35     .     29 

(1,  5)   Pec»a-bed,  Atlierfield. 
(3,  4,  6—9)  Crackers,  Atlierfield. 

(2)  Ferruginous  Sands,  Sliankliu. 
Affinities. — This    species    has  been    referred  by    most    authors    to    the    genus 


(1) 

(2) 

Length 

.     93     . 

,     80 

Height 

.     49 

.     46 

(-) 

(«) 

(9) 

50     . 

,     43     , 

33    mm. 

29 

.     24 

.      19      „ 

PANOPBA.  225 

Panopea,  but  l:)y  some  to  Plenrouiija.^  There  seems  now  to  be  sufficient  evidence 
to  show  that  it  belongs  to  the  former  rather  than  the  latter,  since  the  hinge-margins 
of  the  two  valves  are  alike  and  there  is  no  overlap  of  left  by  the  right  margin  ; 
the  hinge  possesses  the  prominent,  conical  tooth  characteristic  of  Panopm  (Plate 
XXXVI,  fig.  G);  and  a  well-developed,  broad,  external  ligament  is  present  (Plate 
XXXV,  figs.  9  i,  1 1  h).  The  fine  radial  ornamentation  (Plate  XXXV,  figs.  9  c,  13  //) 
agrees  perfectly  with  that  found  in  Tertiary  species  of  Panojjea.''  I  have  not  seen 
the  hinge  in  any  specimen  from  the  Lower  Greensand,  but  it  is  well  preserved  in 
a  left  valve  from  Blackdown.  Pictet  and  Campiche^  state  that  casts  from  the  Aptian 
show  clearly  the  presence  of  the  teeth  of  Panopen. 

Pictet  and  Renevier  thought  that  P.  pUratit  (Sowerby)  and  P.  neocomiensis 
(Leymerie)  should  be  united  as  one  species ;  Pictet  and  Campiche,  however,  in  a 
later  work  regarded  them  as  distinct,  and  stated  that  the  former  differs  from  the 
latter  ])y  the  possession  of  strong  concentric  folds  and  by  the  absence  of  fine  radial 
ornamentation.  But  when  iiumerous  specimens  are  examined  all  stages  in  the 
strength  of  the  folds  can  be  seen  ;  and  those  with  well-developed  folds  show,  when 
the  surface  is  well-preserved,  the  same  kind  of  radial  ornamentation  that  occurs  on 
specimens  with  indistinct  folds.  The  presence  of  a  carina  in  front  of  the  umbones 
and  the  somewhat  smaller  height  of  the  posterior  part  of  the  shell  have  also  been 
mentioned  as  characteristic  of  P.  rtcocomiensix,  but  these  features  are  now  known 
to  be  inconstant.  It  appears,  therefore,  that  there  is  no  character  by  which  P. 
pHcala  can  be  separated  from  P.  neocomiensis. 

It  is  evident  from  Brongniart's  remarks  that  his  specimens  of  Lntrnriu  gurgitis 
came  from  the  Perte-du- Rhone.  Pictet  and  Renevier,^  who  had  seen  the  type  of 
that  species  in  the  collection  of  M.  Deluc,  recognised  it  as  a  specimen  from  the' 
Aptian  of  the  Perte-du-Rhone,  and  state  that  it  is  certainly  an  example  of  either 
P.  neocomiensis  or  P.  plica ta.  Since  these  two  forms  are  now  united  it  follows 
that  the  earlier  name  given  by  Brongniart  should  be  used  for  this  species.  Later 
writers  liiive  unfortunately  used  the  name  gm-gHis  for  a  species  from  the  Chalk. 

P.  acutisulcatd  (Deshayes'')  and  P.  Srhri'xJi'ri  (^Yollemann^)  appear  to  be  closely 
allied  to  P.  gin-gifis. 

1  For  au  accouiit  of  tho  characters  of  this  wenus  see  Terqueni,  '  Bull.  Soc.  geol.  cle  France,'  ser.  3, 
Vol.  X  (1853),  p.  634,  and  "  Observations  sur  les  Etudes  critiques  des  MoUusques  Fossiles  compreuaut 
la  monographie  des  Myaires  de  M.  Agassiz,"  '  Mem.  Acad.  Imp.  de  Metz,'  aimce  1854 — 55  (1855),  p.  253. 

-  See,  for  instance,  P.  intermedin  (Sow.)  from  the  London  Clay,  etc.,  and  P. //orirfrtHot,  Heilprin, 
from  the  Caloosaliatchie  Beds  of  Florida.  '^  '  Terr.  Cret.  Ste.  Croix  '  (18G5),  p.  51. 

'  '  Foss.  Terr.  Aptieu '  (•  Mater.  Pal.  Suisse,'  ser.  1, 1855),  pp.  56  (footnote),  175. 

5  Leymerie,  '  Mcui.  Soc.  geol.  de  France,'  ser.  2,  vol.  v  (1842),  p.  3,  pi.  iii,  fig.  2;  d'Orbigny, 
'  Pal.  Franc.  Terr.  Cn't.,'  vol.  iii  (1845),  p.  336,  pi.  ccclvii,  figs.  1—3  :  Pictet  and  Campiche,  'Terr. 
Crct.  Ste.  Croix"  ('  Mater.  Pal.  Suisse,'  ser.  4,  1865),  p.  65. 

"  '  Die  Biv.  u.  Gastmp.  il.  (Umtscli.  u.  holliind.  Neocoms  '  (' Abhandl.  d.  k.  preussisch.  geol.  Laud., 
N.  F.,  pt.  31,  1900),  p.  126.  pi.  v,  fig.  7. 

30 


22G  CRETACEOUS   LAMELLIBRAXCHIA. 

./'.  heciusfula  (Sowerby'),  from  the  Upper  Greensand  of  Blackdowii,  closely 
resembles  the  small  forms  of  the  neocomiensis  variety  of  P.  gargitis  and  does  not 
appear  to  be  specifically  distinct.  The  type  consists  of  an  imperfect  right  valve ; 
a  specimen  similar  to  the  type,  l)ut  with  both  valves  preserved,  is  in  tlie  Museum 
of  Practical  Geology  (No.  23,823). 

Remarks. — Previous  writers  have  remarked  on  the  great  amount  of  variation 
shown  by  this  species.  At  first  sight  some  of  the  varieties  appear  to  be  distinct, 
but,  as  Wollemaun  has  pointed  out,  when  a  large  number  of  specimens  are 
studied,  transitions  can  be  traced  between  the  different  forms.  The  varieties  do 
not  appear  to  be  confined  to  definite  horizons,  and  nearly  all  of  them  are  found 
together  in  the  Perna-hed  and  Crackers  of  Atherfield. 

Considerable  differences  are  seen  in  the  position  of  the  umbones,  so  that  some 
specimens  are  much  more  inequilatei'al  than  others  ;  in  those  in  which  the  anterior 
part  is  relatively  short  the  anterior  slope  is  rapid.  The  size  and  depth  of  the 
depression  in  the  lunular  region  show  considerable  variation ;  when  large  and 
deep  the  umbones  are  usually  narrower  and  more  pointed  than  when  the  depression 
is  small  and  shallow,  and  in  the  former  case  the  carina  extending  from  the  umbo 
to  the  antero-ventral  margin  is  usually  distinct.  The  relative  length  and  height 
of  the  shell,  the  roimded  or  truncate  character  of  the  anterior  margin,  tlie 
.  curvature  of  the  ventral  margin,  the  height  of  the  posterior  end,  and  the  convexity 
of  the  anterior  compared  with  that  of  the  posterior  part  of  the  shell  also  show 
more  or  less  considerable  differences.  The  concentric  folds  may  be  conspicuous, 
but  ai"e  sometimes  indistinct;  sometimes  they  appear  to  be  better  marked  on 
internal  casts  than  on  the  shell  itself ;  in  some  cases  their  prominence  is  due  to  the 
state  of  preservation  of  the  shell ;  thus  Wollemann  mentions  a  specimen  in 
which  one  valve  is  weathered  and  shows  strong  folds,  whilst  the  other  valve  is 
well  preserved  and  nearly  smooth. 

Some  forms  of  this  species  arc  represented  l)v  a  larger  niiml)er  of  individuals 
than  others.  One  common  form  (Plate  XXXVI,  figs.  3,  4),  agrees  more  or  less 
closely  with  the  type  of  P.  ph'cdfa  (Sowerby),  and  it  may  perhaps  be  convenient 
to  refer  to  this  as  P.  giirgitis  var.  pUrafa.  In  this  the  concentric  folds  are  usually 
prominent,  the  ventral  margin  is  only  slightly  curved,  the  posterior  part  of  the 
shell  is  of  nearly  the  same  height  as  the  anterior  part,  and  the  lunidar  depression 
is  distinct  and  usually  lai'ge. 

Another  form  (Plate  XXXV,  figs.  9,  13)  resembles  P.  neocomiensis  (Leymerie) 
and  may  be  referred  to  as  P.  giirgitis  var.  neocomiensis.     The  concentric  folds  are 

1  Mya  Ixvinscula,  J.  de  C.  Sowerby,  'Trans.  Geol.  Soc.,'  ser.  2  (1836),  vol.  iv,  pp.  241,  340, 
pi.  xvi,  fijr.  6  ;  Morris,  '  Cat.  Brit.  Foss.,'  ed.  2  (1854),  p.  212.  Panopn'a  hevuiscula,  d'Orbignv,  '  Prodr. 
de  Pal.,'  vol.  ii  (1850),  p.  157;  Pictet  and  Campiche,  'Terr.  Cret.  Ste.  Croix'  ('Mater.  Pal.  Suisse," 
ser.  4,  1865),  p.  70. 


PANOPEA.  227 

usually  less  distinct  than  iu  tlie  variety  jjlicatK,  the  luuular  depression  is  smaller 
and  shallower,  the  umbones  broader,  and  the  ventral  margin  usually  more  distinctly 
curved.  The  smaller  specimens  of  the  var.  neocomiensis  resemble  the  example 
figured  by  d'Orbigny,  in  which  the  anterior  margin  is  obliquely  truncated,  and 
a  carina  extends  from  the  umbo  antero-ventrally. 

In  one  form  (Plate  XXXV,  fig.  10),  which  in  other  respects  resembles  the 
variety  neocomiensis,  the  anterior  half  of  the  shell  is  relatively  more  inflated,  and 
the  posterior  part  is  not  so  high  as  the  anterior  part ;  this  form  may  be  known 
as  P.  ijurgilis  var.  a.  In  addition  to  these  forms  of  Z'.  gwrgitis  numerous  other 
modifications  occur. 

Specimens  from  the  Speeton  Clay  have  been  recorded  by  previous  writers  as 
P.  neocomiensis;  the  examples  seen  are  few  in  number  and  not  well  preserved, 
but  resemble  closely  the  smaller  form  of  P.  gun/if  is  var.  neocomiensis  (Plate  XXXV, 
fig.  13).     In  one  case  the  fine,  radial  ornamentation  is  shown. 

Specimens  from  Blackdown  (Plate  XXXVI,  figs.  6,  7)  resemble  the  variety 
2)lic<ifii  from  tlie  Lower  Greensand,  but  are  somewhat  less  convex  ;  these  probablv 
constitute  only  a  local  variety,  since  examples  from  the  Upper  Greensand  of  Dorset 
agree  in  convexity  and  in  other  characters  with  typical  forms  of  the  var.  plicafu 
from  the  Lower  Greensand.  The  examples  from  Blackdown,  although  few  in 
number,  show  considerable  variation;  one  specimen  (Plate  XXXVI,  fig.  8),  is 
nuich  shorter  than  usual,  and  resembles  d'Orbigny's^  figure  of  P.  pUcata,  but 
is  less  convex. 

Crushed  internal  casts  of  Panopea  have  been  found  in  the  Chalk  ]\Iarl  of 
Folkestone ;  they  resemble  P.  gnrgitis  var.  jilicatu,  but  their  imperfect  preservation 
renders  determination  difficult. 

Ti/pes. — The  type  of  1'.  gnrgitis  came  from  the  Aptian  of  the  Perte-dn-lihnne  ; 
that  of  P.  neocomiensis  from  the  Xeocomian  of  Aubc.  The  type  of  /'.  pUcnfn 
was  obtained  from  the  Lower  (Greensand  of  Sandgate,  but  cannot  now  be  found. 
The  type  of  /'.  Igeviuscula,  from  the  Upper  Greensand  of  Blackdown,  is  in  the 
Bristol  iluseum. 

Distriliiition. — Lower  Greensand  :  Perna-hed,  Crackers  and  Beds  iv,  vi,  vii,  x, 
xiii,  and  xiv  of  Atherfield.  P«-/(''-bed  of  Sandown.  Ferruginous  Sands  of  Slianklin. 
Atlierfield  Beds  of  East  Shalford  and  Scvcnoaks.  Hythe  Beds  of  Hythe  and 
Court-at-Street.  Sandgate  Beds  of  Pai  liani  Park.  ^[(lmnliUlJfns  Bed  of  Folke- 
stone. Recorded  1)V  T()})ley  from  the  Atherfield  Chiy  of  Haslemere,  Peasmarsh, 
Redhill,  aiul  Hythe;  from  tlie  Hythe  Beds  of  Pulborough;  from  the  Sandgate 
Beds  of  Folkestone  and  Sandgate ;  and  from  the  Folkestone  Beds  of  Folkestone. 
?  Lower  Greensand  of  L^pware.  PSpceton  Clay  of  Speeton.  Gault  of  Black  Yvu 
and  Folkestone.     Upper  Greensand  of  Blackdown  and  Black  Ven. 

1  '  Pal.  Franc.  Terr.  Crt't.,'  vol.  iii  (1845),  p.  337,  i>\.  ccclvii,  figs.  4,  5. 


228  CRETACEOUS   LAilELLIBRAXCHIA. 

Panopea  mandibcla  iSowerhi/),  1813.     Plate  XXXVII,  figs.  1—5. 

1813.     Mta  mandibtjla,  /.  Sowerby.     Min.  Conch.,  vol.  i,  p.  93,  pi.  xliii. 
?  1840.     Panop.sa  BArMONTii,  A.  Goldfuss.     Petref.  Germ.,  vol.  ii,  p.  274,  pi.  clviii, 

fig.  4. 
?  1841.  —         Jvaj^Eui,  F.  A.  Rnmer.  Die  Verstein.  d.  nord-deutseh.  Kreidegeb., 

p.  75.  pi.  X,  fig.  4. 
1845.  —         MANDiBULA,  A.  d'Oihlyiiy.     Pal.  Fran9.  Terr.  Crt't.,  vol.  iii.p.  344, 

pi.  cccls,  figs.  3,  4. 
1850.  —  —  H.  B.  Geinifz.     Das  Quadersandst.  oder  Kreidegeb. 

iu  Deutschland,  p.  146. 
1854.  Mtacites  mandibula,  /.  Morris.  Cat.  Brit.  Foss.,  ed.  2,  p.  213. 
1865.     Panopea  —  F.  J.  Piclef  and  G.  Campiche.    Terr.  Crt't.  Ste.  Croix 

(Matt'r.  Pal.  Suisse,  ser.  4),  p.  70. 
1870.  —  —  J^.   Stoliczl-a.    Palaeout.  ludica,  Cret.  Fauua  S.  ludia, 

vol.  iii,  p.  87. 
1873.  —  —  H.B.  GeiiiUz.     Das  Elbthalgeb.   iu  Sachseu    (Pal- 

aeontographica,  vol.  xx,  pt.  2),  p. 
70,  pi.  xviii,  figs.  20,  21. 
?  1883.  —  —  A.  Fritscli.      Stud,  im  Gebiete  der  bohm.   Kreide- 

forinat.,  iii,  Iserschielit.,  p.  108. 
?  1897.  —  —  Friisch.     Ibid.,  vi,  Chlomek.  Sc-hiolit.,  p.  60. 

1900.     Pi,EUBOMT.\       —  A.  J.  JiiJces-Broicne.     Cret.  Eocks  of  Britain,  vol.  i, 

p.  470. 

Description.  —  Shell  oblong  or  rliomboidal  in  outline,  very  inequilateral, 
convex,  anterior  part  sloping  rapidlj^to  the  anterior  margin,  with  a  wide  posterior 
gape.  Anterior  margin  somewhat  convex  ;  antero-ventral  extremity  rounded ; 
ventral  margin  straight  or  slightly  curved  and  neai'ly  parallel  to  the  dorsal 
margin;  postero-A'entral  extremity  rounded  ;  posterior  margin  truncated,  nearly 
straight,  either  perpendicular  or  slightly  oblique  to  the  nearly  straight  postero- 
■dorsal  margin.  Unibones  prominent,  narrow,  pointed,  considerably  incurved, 
with  a  In'oad,  .shallow  furrow  extending  from  their  posterior  side  to  the  postero- 
ventral  i)art  of  the  valves.  In  front  of  the  umbones  the  shell  is  considerably 
depressed. 

Ornamentation  consists  of  strong,  rounded,  concentric  folds,  which  become 
less  distinct  in  and  posterior  to  the  dorso-ventral  furrow;  and  of  radial  rows  of 
minute  granules. 

Measurements  ; 


(1) 

(2) 

(3) 

W 

(5) 

(6) 

Length 

72     , 

.     70     , 

.     53 

.     53     , 

,     49     , 

36  mm 

Height 

57     . 

.     46     . 

41 

.     38     . 

.     35     . 

33     „ 

Thickness  . 

41 

.     39 

— 

.     28 

.     20     , 

.     27     „ 

(1,  4 — 6)  Upper  Greensand,  Veutuor. 
(2,  3)  Upper  Greensaud,  Devizes. 


PANOPBA.  229 

Affinities. — Tlie  more  elongate  forms  of  this  species  resemble  some  specimens 
of  /'.  (in)-(jitis  var.  pUcata,  but  are  more  inetiuilatcral,  more  convex,  usually 
relatively  longer,  with  narrower  and  more  pointed  unibones,  and  with  a  distinct 
furrow  extending  from  the  undjo  to  the  postero-ventral  margin. 

Uemarks. — Many  of  the  specimens  are  more  or  less  crushed,  and  nearly  all  are 
internal  casts,  but  the  shell  is  preserved  in  some  specimens  from  the  (lault,  and 
shows  radial  rows  of  fine  granules.  The  hinge  is  not  seen  in  any  instance. 
P.  mandilnda  is  common  in  the  Upper  Greensand  of  Ventnor  and  Devizes,  and  is 
less  abundant  at  other  horizons.  The  principal  variation  seen  is  in  the  relative 
length  and  heio-ht  of  the  shell. 

Type. — From  the  Upper  Greensand  of  Devizes,  in  the  British  Museum. 

Distribution. — Lower  Greensand  of  Atherfield.  Atherfield  Beds  of  Seveuoaks. 
Sandgate  Beds  of  Nuffield.  Folkestone  Beds  of  Folkestone.  Upper  Greensand 
(zone  of  SrJihvnhachia  rostrata)  of  Devizes  and  Yentnor.  Gault  and  Upper 
Greensand  of  Black  Ven.     Chalk  Marl  of  Folkestone. 


Panopea  ovalis,  Soicerhij,  18:36.     Plate  XXXVII,  fig.  Q>a,h. 

1836.     Panopea  ovalis,  J.  cle  C.  Sowerby.     Traus.  Geol.  Soc,  ser.  2,  vol.  iv,  pp. 

241,  340,  pi.  xvi,  fig.  5. 
1850.  —  —       A.  iVOrhiijny.     Prodr.  cle  Pal,  vol.  ii,  p.  157. 

1854.     Myacites       —       /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  214. 

Description. — Shell  oval,  convex,  moderately  inequilateral.  Antero-dorsal 
margin  slightly  convex ;  anterior  margin  rounded,  passing  gradually  into  the 
slightly  convex  ventral  margin.  Unibones  broad,  incurved.  The  parts  of  the 
shell  in  the  front  of  and  Ijehind  the  umbones  are  considerably  dejjressed.  The 
surface  is  ornamented  with  growth-rings. 

Remarls. — The  only  specimen  seen  is  the  t\'pe,  in  which  the  posterior  part  of 
the  shell  is  not  preserved. 

Tijpe.- — 111  the  British  ]\Iuseuiii. 

Distribution. — Upjier  (ireensand  (zone  of  Schluinbackia  ro.ftratu)  of  Blackdown. 


P.\xoPE.\  Meyeri,  sp.  nov.     Plate  XXXVIII,  fig.  la,b. 

Desiuiptiun. — Shell    oval,    moderately    convex,    witli    flattened    sides,    slightly 
inequilateral,  with  a  wide  posterior  gape.    Antero-dorsal  margin  convex.    Anterior 


230  CRETACEOUS   LAMELLIBRANCHIA. 

margin  rounded.  Ventral  margin  straight  or  slightly  convex.  Posterior  margin 
truncated,  sliglitl}-  convex.  Postero-dorsal  margin  slightly  concave,  nearly  parallel 
to  the  ventral  margin.  Umbones  broad,  curved  inwards  and  backwards.  The 
part  of  the  shell  in  front  of  the  umbones  is  slightly  depressed;  the  part  behind  the 
umbones  is  more  deeply  depressed.  Surface  with  well-marked  growth-rings. 
Length  87  mm. ;  height  59  mm. 

Aj)i)iifies. — In  this  species  the  sides  of  the  shell  are  more  flattened,  the  autero- 
dorsal  margin  is  more  convex,  and  the  part  of  the  shell  in  front  of  the  umbones  is 
less  depressed  than  in  P.  ocdlis.  The  hinge  has  not  been  seen,  but  the  form  of  the 
shell  agrees  closely  with  that  of  ty})ical  species  of  Panopea. 


Fig.  28. — Panopea,  sp.     Lower  Greeiisand  ('  .-^capniti's      J.rtls),  Whale  Chine,  Atherfield.     Sed-jwick 
Museum.     Internal  cast  of  right  valve.     Natural  size. 

Jt'riitarkt^. — In  addition  to  the  specimen  figured,  which  was  collected  by 
C.  J.  A.  Meyer,  an  internal  cast  and  the  posterior  part  of  a  left  valve  only  have 
been  seen. 

Distribution. — Upper  Greensand  (zone  of  ScliUviilntchid  rarinna)  of  Blackdown. 


P.\xnpj;,\,  sp.     Text-fig.  28. 

Internal  casts  resembling  /'.  ^Li'ijcri,  but  with  the  po.■^terior  border  obliquely 
truncated,  occur  in  the  Lower  Greensand  ("  Scaphites "  Beds)  of  "Whale  Chine, 
Atherfield. 


MARTESIA.  231 

ira„ji/^_PHOLADID.E,  Leach. 

Genus — Martesia,  Leach  in  H.  M.  D.  rie  Blainville,  1825. 
('  Manuel  de  Malacol.,'  p.  632.) 

Maetesia  coNSTEiCTA  (rJuIUps),  1829.     Plate  XXXVIII,  figs.  3—10. 

1829.     Pholas  constricta,  /.  PJiilhyi.     Geol.  Torks.,p.  169  (p.  256,  ed.  3),  pi.  ii, 

%.  17. 
1850.  —  —A.  d'Orbigny.     Prodr.  de  Pal.,  vol.  ii,  p.  117. 

1854.  —  —  J.Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  221. 

1864.  —  —  F.J.  Field  and  G.  Campiclie.     Foss.  Terr.  Crit.  Ste. 

Croix  (Mater.  Pal.  Suisse,  ser.  4), 
p.  26. 
1870.  —  —  F.  Stoliczka.     Palisout.  ludica,  Cret.  Fauua  S.  ludia, 

p.  23  (?  Martesia). 
1900.     Pholadidea  constricta,  A.  J.  Jukes-Browne.      Cret.   Eocks  of  Britain, 

vol.  i,  p.  470. 

Description. —  Shell  small,  more  or  less  elongate;  anterior  part  short,  convex, 
rounded ;  posterior  part  wedge-shaped.  Umbones  prominent,  close  together, 
curved  inwards  and  forwards.  Ventral  margin  nearly  straight.  Posterior  margin 
sub-truncate,  more  or  less  rounded,  somewhat  oblique.  Postero-dorsal  margin 
sloping  ventralh'.  Two  narrow  furrows,  with  corresponding  internal  ribs,  extend 
from  the  umbo  to  the  ventral  margin;  the  anterior  furrow  is  rather  broader  and 
less  oblique  than  the  posterior,  i)ut  is  sometimes  short  or  absent.  An  internal » 
ridge,  near  the  postero-dorsal  margin,  extends  from  the  umbo  to  near  the  posterior 
adductor.  Anterior  callus  shield-shaped.  Ventral  margin  of  valves  diverging 
posteriorly,  joined  by  a  hypojdax.     Metaplax  elongated,  divided. 

Ornamentation  :  on  the  larger  part  of  the  shell  distinct,  regular,  concentric 
ribs  with  minute  transverse  sei-rations.  In  front  of  the  anterior  furrow  the  ribs 
become  smaller  and  closer  together;  they  ])end  dorsally  and  unite  at  an  angle 
with  similar  ribs  on  the  dorsal  })art  of  the  anterior  end  of  the  valve.  On  the 
postero-dorsal  part  of  the  shell  the  ribs  are  less  regular  and  less  distinct. 

Measurements : 

(2)  (3)  (4)  (.^>) 

17    .    k;    .    18    .    15 

9     .       9     .     10     .       9 

9.9.     10-5.       9 

(1 — 3)  Speeton,  (4 — 7)  Folkestone. 

Affinities. — This  species  is  less  elongate  than  M.   subcijlindrica  (d'Orbigny).' 
1  '  Pal.  Franc.  Terr.  Crot.,'  vol.  iii  (1845),  p.  306,  pi.  cccxlix,  figs.  5—8. 


(1) 

Length 

18 

Height      . 

9 

Thickness 

9 

(6) 

(7) 

14     . 

10      mm 

7 

C-5    „ 

7.5  . 

6-5    „ 

232  CRETACEOUS    T,A:yrETJJBRANCHIA. 

Tlie  height  of  tlie  anterior  part  of  the  sliell  is  less  and  the  length  of  the  ventral 
margin  greater  relatively  than  in  M.  Sandse-CnirU  (Pictet  and  Campiche).' 

Remarks. — This  species  varies  somewliat  in  relative  length  and  breadth,  and 
in  the  extent  of  the  develo^Jment  of  the  anterior  furrow.  Many  of  the  specimens 
are  found  in  burrows  in  Avood.     The  protoplax  is  not  preserved  in  any  example  seen. 

T//pe. — The  type  came  from  Speeton,  but  cannot  now  be  found. 

DistrihuHon. — Speeton  Clay  of  Speeton.  Lower  and  Upper  Gault  of  Folkestone. 
Probably  also  in  the  Upper  Greensand  of  Blackdown.  Specimens  wliifh  belong  to 
either  this  or  a  closely  allied  species  occur  in  the  Spilsby  Sandstone  of  Benniworth 
Haven.  Borings  in  wood  found  in  the  Tealby  Limestone  of  Claxb}-  may  lie  due 
to  this  species  but  the  valves  are  concealed. 

Martesia  ruiscA  (Soirerhi/),  1828.     Plate  XXXVIII,  fig.  11. 

]828.     Pholas  priscus,  /.  c!e  C.  Sowerhy.     Miu.  Couch.,  vol.  vi,  p.  157,  ]il.  dlxxxi. 

1845.     Pholas  ?  priscus,  E.  Forbes.     Quart.  Jourii.  Geol.  Soc,  vol.  i,  p.  "237. 

1850.     Pholas  prisca,  A.  d'Orbigny.     Prodr.  de  Pal.,  vol.  ii,  p.  72. 

1854.  —  —      J.Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  221. 

1864.  -  —      F.  /.  Pidet  and  G.  Campiche.     Foss.  Terr.  Crct.  Ste.  Croix 

(Matt'r.  Pal.  Suisse,  ser.  4),  p.  26. 
1870.  —  — •      (Martbsia),  F.  Stoliczha.     Palaeout.  ludica,  Cret.  Fauna 

S.  ludia,  vol.  iii,  p.  22. 
1875.     Pholadidea  prisca,  B.  Etheridge  iii  W.  Topley.     Geol.  Weald,  p.  419. 

This  species  appears  to  be  closely  related  to  ill.  constricfa,  but  no  satisfactory 

description  can  be  given  until  better  specimens  have  been  obtained.     The  type,  in 

which  the  shell  was  well  preserved,  cannot  now  be  traced  ;  in  other  examples  the 

shell  is  concealed  by  a  coating  of  hard  matrix,  and  in  the  few  cases  in  which  it  has 

been  possible  to  remove  the  matrix  only  internal  casts  of  the  valves  have  been 

exposed.     The  type   came   from  the  Lower  Greensand   (?  Sandgate    Beds)    near 

Sandgate.      Other  specimens  have  been  obtained  from  the  Hythe  Beds  of  Hythe 

and  Maidstone." 

1  'Foss.  Terr.  Cret.  Ste.  Croix'  (1864),  p.  24,  pi.  c,  tig.  1.  This  species  has  been  recorded  by 
Price  from  the  Gault  of  Folkestone ;  I  have  not  seen  any  examples  of  it. 

-  Fistulana  pijriformis,  Mautell,  is  perhaps  a  Martesia,  but  no  specimens  showing  the  valves  have 
been  seen.  No  figure  or  specific  description  was  given  by  Mautell.  The  "type"  came  from 
■VVillingdon  near  Eastbourne,  apparently  from  the  top  of  the  Lower  Greensand.  Mantell,  '  Foss.  S. 
Downs'  (1822),  p.  76-  Gastrochiena  pyri/ormis,  Morris,  'Cat.  Brit.  Foss.,'  ed.  2  (1854),  p.  203; 
Pictet  and  Campiche,  '  Foss.  Terr.  Crct.  Ste.  Croix  (Mater.  Pal.  Suisse,'  ser.  4,  1864),  p.  18  ;  Stoliczka, 
'Palseont.  ludica,  Cret.  Fauna  S.  India,'  vol.  iii  (1870),  p.  29. 

Gastrochwna  dilatafa,  Deshayes,  has  been  recorded  by  Forbes  and  other  writers  from  the  Lower 
Greeusand  ;  I  have  not  seen  an_y  specimens  in  which  the  valves  are  exposed.  Deshayes,  in  Leymerie, 
'  Mem.  Soc.  geol.  de  France,'  vol.  v  (1842),  p.  2,  pi.  iii,  fig.  1 ;  Forbes,  '  Quart.  Jouru.  Geol.  Soc.,'  vol.  i 
(1845),  p.  237 ;  Pictet  and  Campiche,  '  Foss.  Terr.  Cret.  Ste.  Croix '  (1864) ,  p.  1 1 ,  pi.  xcix.  figs.  4.  5. 


TURNUS.  233 


Martesia?  kotuxda  {Soirn-hi/),  18-50.     Plate  XXXVIII,  figs.  12  (t—c,  18. 

1850.     Teredo  eotundtjs,  J.  de  C.  Sowei-hy  iu  F.  Dixon.     Geol.  Sussex,  p.  340  (p. 

382,  ed.  2),  pi.  xxviii,  figs.  27,  28. 
1854.  —  —         /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  227. 

1897.     Martesia  ?  rotunda,    H.    Wnixh.      Quart.    Jouru.    Geol.    Soc,   vol.    liii, 

p.  393,  pi.  xxviii,  figs.  15 — 18. 

Description. — Shell  small,  ovoid,  inflated,  with  rounded  outline.  Anterior  gape 
large,  apparently  closed  by  callus.  Umbones  sub-median,  curved  inwards  and 
forwards.  A  strong  groove  and  a  corresponding  internal  rib  pass  from  the  umbo 
to  the  ventral  margin.  Near  the  dorsal  margin  a  strong,  narrow  internal  rib  passes 
backward  from  the  umbo  but  does  not  reach  the  posterior  margin.  Ornamentation 
posterior  to  the  groove  consists  of  concentric  ribs  and  of  two  radial  ribs  imme- 
diately behind  the  gi'oove;  anterior  to  the  groove  are  a  few  regular  radial  ribs,  and 
concentric  ribs  parallel  to  the  margin  of  the  anterior  gape.  Length,  7  mm. ; 
height,  5'5  mm. ;  thickness,  5  mm. 

Bemarlis. — I  have  seen  only  three  casts  of  the  interior  and  two  of  part  of  the 
exterior  of  this  species,  so  that  at  jjresent  it  is  difficult  to  determine  satisfactorily 
its  generic  position. 

Type. — The  type  came  from  the  Chalk  of  Kent,  l)ut  cannot  noAV  l)e  found. 

Distribiitiuu. — Chalk  Rock  of  Cnckhamsley  (Berkshire),  and  of  AVhyteleafc 
(Surrey). 


Genus— TuR^vn,  W.  M.  GahJ,,  ISGl. 
('  Geol.  Surv.  California,'  Pala;outology,  vol.  i,  p.  145.) 

TuRNUs  Dallasi  {Wall-cr),  1866.     Plate  XXXVIII,  figs.  14  a,  h,  15. 

18(3(5.     Pholas  Dallasi,  /.  F.  Walker.     Ann.  Mag.  Nat.  Hist.,  ser.  3,  vol.  xviii, 

p.  38(5,  pi.  xiii,  figs.  3,  4. 

De.^crij)ti()n. — Shell  ovate,  short,  inflated  in  front,  wedge-like  behind.  Margin 
of  the  anterior  gape  oblirjue,  gently  curved.  Posterior  margin  rounded.  Umbones 
prominent,  curved  inwards  and  forwards.  A  narrow  furrow,  and  a  corresponding 
internal  rib,  extend  from  the  umbo  to  the  ventral  margin  in  a  somewhat  oblique 

dirt'ctiiin,  and  the  furrow  is  crossed  by  small  ril).s.  A  liruad  and  strong  internal  ril> 

31 


284  CRETACEOUS   LAMELLIBRAXCHIA. 

passes  from  the  umbo  to  near  the  postero-ventral  margin.  The  shell  is  ornamentetl 
with  small  concentric  ribs,  which  bend  dorsally  in  front  of  the  furrow  and  become 
parallel  to  the  anterior  margin. 

Measurements  : 

(1)  (2) 

Length  .  .  .  15         .         S      mm. 

Height  .  .  .  11         .         0-5      ., 

Thickness  .  .  .  —         .         (rb      ,, 

Affinities. — The  very  slight  curvature  of  the  anterior  margin  and  nf  the  anterior 
ribs  distinguishes  this  species  from  the  one  described  below. 

Remarlcs. —  T.  DaUasi  occurs  commonly  boring  in  wood. 

Ti/2w. — From  Potton  ;  in  the  Sedgwick  Museum. 

Dintrihufion. — Lower  Greensand  of  Potton. 


TuRNUS,  sp.     Plate  XXXVIII,  figs.  KJ,  17. 

Descrijdiun. — Shell  oval,  inflated,  posterior  end  wedge-like.  Ventral  margin 
curved  ;  posterior  mai'gin  rounded.  Antero-ventral  excavation  angular.  Umbones 
prominent,  anterior,  incurved,  close  together.  An  external  furrow  and  a  correspond- 
ing internal  rib  extend  from  the  umbo  to  the  ventral  margin.  A  strong  internal 
rib  passes  from  the  i;mbo  to  near  the  postero-ventral  edge. 

Posterior  to  the  dorso-ventral  groove  the  shell  is  ornamented  with  narrow, 
regular  concentric  ribs  ;  for  a  short  distance  in  front  of  the  groove  the  ribs  bend 
sharply  upwards,  and  soon  become  smaller  and  close  together ;  on  the  dorsal  part 
of  the  anterior  end  the  I'ibs  I)end  forwards. 

Measurements  ; 

(1)  (2) 

Length  .  .  .  14  .         13  mm. 

Height  .  .  .  11  .  9-5„ 

Thickness        .  .  .  12  .         10     „ 

(1—2)  Gault,  Folkestone. 

Affinities. — This  species  resembles  T.  argoiinensis  (Buvignier),^  but  exact 
comparison  is  difficult  since  only  a  small  internal  cast  is  figured  by  Buvignier. 
The  English  form  appears  to  differ  from  T.  argonneasis  in  the  larger  size  and 
more  angular  character  of  the  anterior  gape,  and  in  the  smaller  and  closer  ribs, 
especially  on  the  anterior  part  of  the  shell. 

Disfributioii. — Lower  Gault  of  Folkestone. 

1  '  Statist,  ycul.  iiiiu.  ot  jiak-out.  de  la  Meuse,'  Atlas  (1852),  p.  6,  pi.  vi,  figs.  33—39. 


TURNU8.  2:35 


TuKNOS,  sp.     Plate  XXXVIII,  fig-.  18. 

A  specimen  from  the  Upper  Greensancl  of  Blackdown  resembles  the  species 
from  the  Gaiilt,  described  above,  but  the  concentric  ribs  are  finer  and  more 
numerous,  antl  the  dorso-ventral  furrow  is  narrower.  The  exterior  of  a  left  valve 
only  is  preserved  and  is  associated  with  large  aud  rather  irregular  tubes. 


TuRNUS  ?  AMPHiSB.Ex\A  (Guldfuss),  1831.     Plate  XXXVIII,  figs.  19,  20. 

1822.     Teredo,  G.  MaiiteU.     Foss.  S.  Downs,  p.  2u7,  pi.  .wiii,  fiy.  2-3. 
1831.     Sebpula  amphisb^ena,  A.  GoJdfuss.     Petref.  Gremi.,  vol.  i,  p.  239,  pi.  Ixx, 

%'.  16. 
r  1839.     Ceeambtcites,  sp.,  H.  B.  GtinUz.     Char.  d.  ScLiclit.  u.  Petref.  des  siichs. 

Kreidegeb.,  pt.  1,  p.  13,  pis.  iii — vi. 

1840.  Teredo  amphisb^na,  /.  de  C.  Sowerhy.     Miu.  Couch.,  vol.   vii,  p.  17,  pi. 

dcxviii,  figs.  1 — 5  {Teredo  articu- 
Ictta  ou  the  plate). 

1841.  Serpula  amphisb.ena,  F.  A.  RiViner.       Die    Verstein.    d.    uord-dtnitsch. 

Kreidegeb.,  p.  100. 

1842.  —  —  H.  B.  Geiiiitz.     Char.    d.    Schicht.    u.    Petref.   des 

siichs. -bohmiscli.  Kreidegeb.,  pt.  3, 
p.  6.5. 

1843.  Fistulana  amphisb.ena,  if.  jB.  ti'ci'/nVx.     Die  Versteiu.  vou  Kiesliugswalda, 

p.  11,  pi.  iv,  figs.  11 — 14. 

1845.  SERPrLA  XM.vaisBj&j^\,  A.E.Reuss.    DieVersteiu.derbohni.Kreideformat., 

pt.  1,  p.  19,  pi.  v,  figs.  29—32. 

1846.  Gastroch.5:na  ?  (Teredo  r)  amphisb^na,  H.  B.  Geiiiitz.     Gruudr.  d.  Ver- 

stein., p.  396. 
':*  1850.     Fistulana  amphisbjjna,  P.  de  EycMolt.     Melanges  Pak'ont.  i  (Mem.  eour. 

et  Mem.  des  sav.  eti-aug.,  vol. 
xxiv),p.  117,  pi.  V,  figs.  19—22. 

1850.  Teredo  amphisbcena,  /.  de  C.  Sowerhy,  in  F.  Dixon.     Geol.  Sussex,  p.  354 

(p.  385,  ed.  2),  pi.  xxviii,  fig.  35. 

1851.  Gastroch^ina  amphisb^.na,  J.  Midler.     Petref.  der  Aaeheu.  Kreidef.,  pt.  2, 

p.  63. 
?1852.  —  —  ?,  Ji'.A'we/-.  Denksehr.  d.k.  Akad.  d.  Wisseusch. 

Wien,    Math.-nat.   CI.,   vol.    iii, 
p.  310,  pi.  xvi,  fig.  18. 
1854.     Teredo  amphisb.«na,  J.  Morris.     Cat.  Brit.  Foss  ,  ed.  2,  p.  227. 

1863.  Gastroch^na  amphisbjena,  li.    Drescher.       Zeitsehr.    d.     deutsch.    geol. 

Gesellsch.,  vol.  xv,  p.  341. 

1864.  —  F.  J.  Pictel  and  G.  Campiche.   Foss.  Terr.  Cret. 

Ste.  Croix  (Mater.  Pal.  Suisse, 
ser.  4),  p.  19. 


230  CRETACEOUS   LAMELLIBRANCHIA. 

1870.     Teredo  amphisb^sina,  J''.  RiJmer.     Geol.  v.  Oberschles.,  jip.   ;517,   'S-iO,    pi. 

xxxiv,  figs.  14,  15. 

—  Gastroch^ena  AMPHiSBiENA,  F.  Sfoliczka.     PalsDoiit.   ludica,  Cret.  Fauna 

S.  India,  pp.  14,  29. 
1873.  —  —  I[.  n.  Gehilfz.     Das   Ell)thal<,'eb.  in    Sacliscn 

(Palfeontograpliica,  vol.  xx, 
pt.  1),  p.  235,  pi.  lii,  figs. 
8—12. 

1876.  —  —  D.  Braurnt.     Zeitsclir.  f.  d.  gesamiut.  Natur- 

iviss.,  vol.  xlvi,  p.  358. 

1877.  —  — ■  A.  Frilsch.      Stud,    iiu    Gebiete    der    biilmi. 

Kreideformat.  ii,  AVeisseuberg.  u.  Malnitz. 
Sehiclit.,  p.  122,  fig.  93. 

1888.  —  —  G.  Miilhr.      Jalirb.    d.    k.    preussisch.    geol. 

Landesaust.  f  iir  1887,  p.  436. 

1889.  —  - —  A.  FritsrJi.      Stud,    ini    Gebiete    der    bijlnn. 

Kreideformat.     iv,     Teplitz. 
Scliicht.,  p.  79,  fig.  G7. 

—  —  —  0.  Griepenkerl.     Senou.  v.  Konigslutter  (Pal- 

ffiout.  Abhandl.,   vol.    iv), 
p.  69,  (?  pi.  vii,  fig.  1). 
?  1889.    ?         —  —  E.  Hohapfel     Die  Mollusk.  Aachen.  Kreide 

(Palseoutographiea,  vol.  xxxv),  p.  143. 
?  1893.  —  —  Fritsch.     Op.  cit.  v.  Priesen.  Scliicht.,  p.  9Q, 

fig.  113. 
?1895.    ?         —  —  F.  Vogel.     Hollundisch.  Kreide,  p.  49,  pi.  iii, 

fig.  13. 

1897.  —  —  a.  Leonhard.     Kreideformat.    in    Oberschles. 

(Palaeontograpliica,  xliv),  p. 
53,  fig.  8. 

1898.  TuRNUs  AMPHiSB^NA,  6'.  !/''//(;/•.     Mollusk.  d.  Uuterseuon  V.  P>rauuscliweig 

u.  Ilsede  (Abhaudl.  d.  k.  preuss.  geol. 
Laudesanst.,  N.  P.,  Heft  25),  p.  79, 
pi.  X,  fig.  12. 
1902.         —  —  A.  WoUemann.     Fauna  der  Li'ineburg.  Kreide  (Ab- 

haudl. d.  k.  preuss.  geol.  Landes- 
anst.  N.  F..  Heft  37),  p.  81. 

Description. — Tubes  long,  conical,  tajjering  gradually,  sonietiraes  nearly  straight, 
but  usually  beudiug  or  curviiig  ii'vegularly,  circular  in  scrtioii,  but  often  com- 
pressed, and  then  showing  a  median  longitudinal  furrow  on  one  side.  Diameter 
sometimes  reaches  15  mm.  and  the  length  210  mm.  Surface  with  narrow^  transverse 
ridges  at  more  or  less  regular  intervals  giving  a  segmented  appearance ;  sometimes 
also  with  smaller  growth-rings  between  the  ridges. 

Remarks. — This  species  ranges  almost  throughout  the  Chalk  and  is  widely 
distributed.     It  has  been  referred  l)y  various  authors  to  five  different  genera,  but 


TEREDO.  237 

its  systematic  position  must  still  be  regarded  as  uncertain,  tor  altliougli  the  tubes 
ai'e  common  the  valves  Lave  not  been  found  in  association  Avitli  them.  Fritscli 
(1893)  and  MiiUer  (1898)  liave  Found  the  valves  of  'I'lrnnis  in  the  same  deposit  as 
the  tubes,  and  think  it  probable  that  the  former  belong  to  the  same  species  as  the 
latter.  Some  authors  have  referred  these  tubes  to  the  genus  (lastrorlin'i/u,  l)ut 
Stoliczka  points  out  that  the}^  resemljle  more  nearly  the  tubes  of  Teredo. 

Tijpea. — From  the  Senonian  of  Maestricht  and  Bochum.  The  specimens 
figured  by  Sowerby  (except  fig.  2,  which  is  in  the  British  Museum),  by  Mantel),  and 
by  Dixon  cannot  l^e  found. 

Disfriliittioii. — C'hloritic  Marl  of  Eastbourne.  (Aunbridge  Greensaud.  Chalk 
IMarl  of  Chard  and  Ventnor.  Zone  of  Holaster  suhglobosus  of  Holborongh  near 
Eochester,  Totternhoe,  Cherry  Hinton,  and  Burwell.  Zone  of  Bliijnclionella  Cuvieri 
of  the  Devon  coast,  Winchester,  the  Isle  of  AVight,  and  Lewes.  Zone  of  Terehra- 
tidiiKi  of  Winchester,  the  Isle  of  AVight,  Croydon,  and  Devon.  Zone  of  Holaster 
phinus  of  the  Dorset  coast,  the  Isle  of  Wight,  Dover,  and  Lnton.  Zone  of  Micraster 
cor-teshuVuutr'uim  of  Mitcheldevei-,  Dover,  the  Sussex  coast,  and  Coulsdon  (Surrey). 
Zone  of  M.  cor-nnguinuin  of  the  Sussex  coast,  St.  Margaret's,  Thanet,  and  Graves- 
end.  Zone  of  Marsiijntes  tcstiidinarius  of  Highfield,  near  Salisburj-,  the  Sussex 
coast,  and  Thanet.     Zone  of  Actiuncnmax  qitiidriifns  of  the  Sussex  coast. 


i^tr/H////— TEREDINID.E,  Scacchi 

Genus — Tkreuo,  Liiuia'its,  1758. 
('  Syst.  Nat.,'  ed.  10,  p.  651 ;  ed.  12,  1767,  p.  1267.) 

Tehedo  GAUi/nxA,  sp.  nov.     Plate  XXXVIII,  fig.  21. 

Prscri/ilioii — Shell  convex,  inequilateral.  Anterior  gape  large,  angular. 
Postero-veutral  gape  small.  Postero-dorsal  margin  produced  upwards  and  out- 
wards. L'mbones  large,  incurved.  A  shallow  furrow  extends  from  the  umbo  to 
the  ventral  margin.  Posterior  to  the  furrow  the  shell  is  ornamented  with  ribs  and 
narrow  furi-ows,  which  soon  bend  iloi'sally,  and  disappear  or  become  indistinct  on 
the  postero-doi-sal  part;  in  front  of  the  furrow  tiie  ribs  are  much  smaller,  and 
are  pai'alld  to  the  margin  of  tlie  anterioi'  ga[ie;  at  first  they  are  directed  dorsally, 
but  soon  bentl  forwards.     Length,  9  mm. ;  l)readth,  8"-j  mm. 

Affinities. — In  1\  rarennensis,  Buvignier,^  the  anterior  ribs  are  coarser  and  the 
posterior  end  of  the  shell  is  more  produced  than  in  this  species. 

Distribution. —  Gault  of  Folkestone. 

1  '  Statist.  i,'('ol.  mill,  ot  paKVmt.  de  hi  Meiise,"  Atlas  (1852),  p.  6,  pi.  vi,  figs.  40—48. 


238  CRETACEOUS   LAMELLIBRANCHIA. 


Genus — Pi.ECTOJiYA,  P.  de  Lnriul,  1868. 
(De  Loriol  and  Cotteau,  '  Mou.  Pali'oiit.  GtoI.  Portlandii-n  Jo  I'Yonne,'  p.  89.) 

Plectomya  Axrir.icA,  sp.  iiov.     Plate  XXXIX,  fig.  In,  J,. 

Description. — Sliell  elongate-oval,  slightly  ineciuilateral,  compressed;  anterior 
and  posterior  ends  rounded  j  ventral  margin  slightly  convex.  Umboues  broad, 
A\  ith  a  sliglit  posterior  cm*vature. 

The  part  of  the  shell  in  front  of  a  line  drawn  fi'om  the  umlio  to  the  opposite 
ventral  margin  is  ornamented  Avith  strong  concentric  ribs  separated  by  broad 
furrows ;  these  ribs  become  nearly  or  quite  obsolete  on  the  posterior  middle  part 
of  the  shell  (except  near  the  umbo),  but  re-appear  on  the  postero-dorsal  part. 
The  entire  surface  of  the  shell  is  ornamented  with  numerous  radial  rows  of 
granules.     Length  49  nun  ;  height  27  mm. 

Affinities. — This  species  is  similar  in  general  character  to  rjertointja  Agassizi 
(d'Orbigny'),  but  the  shell  is  less  elongate,  the  ribs  on  the  anterior  part  of  the 
shell  cut  the  margin  and  the  growth-lines  obliquely,  and  on  the  jjosterior  median 
part  the  ribs  are  almost  obsolete.  It  also  shows  some  resemblance  to  1'.  EhoJiini 
(Pictet  and  Ronx'-). 

liemarl-s. — Of  this  species  I  have  seen  only  two  examples,  neither  of  which 
shows  the  interior,  so  that  I  am  unaljle  to  express  an  opinion  as  to  afUnities  of  the 
genus  I'lecloiiujii. 

]>isfribntii)ii. — Lower  Greensand  (Crackers)  of  Atherfield." 


Genus — Anatixa,  Lninarcl-,  ISdU. 
('  Philosoph.  Zool,"  vi)l.  i,  p.  31SI  ;  '  Hist.  iiat.  Auiiii.  saiis  Vert.,'  vol.  v,  1818,  p.  462.) 

Suh-(jenus — Ceucumya,  L.  Aijassb.,  1S42. 
('  Etudes  crit.  Moll.  Foss.,"  Myes,  p.  143.) 

1  'Pal.  Franc.  Terr.  Cn't.,'  vol.  iii  (1845),  p.  371,  pi.  ci-cl.xix,  figs.  1,  2;  Pictet  and  Caiupiche, 
'Foss.  Terr.  Crct.  Ste.  Croix'  ('Mater.  Pal.  Suisse,'  ser.  4,  1865),  p.  99,  pi.  cvii,  fig.  1. 

-  '  Moll.  Foss.  Gres  verts  de  Geneve'  (1852),  p.  410,  pi.  xxix,  fig.  4. 

*  An  imperfect  specimen  from  the  Lower  Greensand  of  Atherfield  is  probably  an  e.vample  of 
Plectomya  maruUensis  (d'Orbigny),  op.  cit.,  p.  376,  pi.  ccclxxi,  figs.  3,  4  ;  Pictet  and  Campiche,  op.  cit., 
p.  101,  pi.  cvii,  figs.  2,  3. 


ANATINA.  239 


Anatina  (Cekcoxiya)  (iriiciTis,  ricfft  and  Cdm/iirln',  18()5.     Plato  XXXTX,  figs.  2 — 4. 

1855.     Anatina  'RoTiivsxi.intiK.  F.  J.  Pidet  and  E.  Renevier.      Foss.  Terr.   Aj/tii'ii 

(Mati'r.  Pal.  Suisse,  ser.  1),  p.  63,  pi.  vii,  li>,'.  1. 
(Nou  A.  Robinaldina ,  d'Orbigny,  1845.) 
1865.  GURGiTis,  F.  J.  Pictet  and  G.  Campiche.     Fo.ss.  Terr.  Cri't.  Ste. 

Croix  (Mat('r.  Pal.  Suisse,  ser.  4), 
p.  105,  pi.  cvii,  figs.  6—8. 
1870.  —         (Cercomya)  GDRGiTis,  J'.  <S7o/iC2/.-a.    Palaeont.  Iiiilica,  Cn-t.  Fauna 

S.  ludia,  vol.  iii,  ji,  "4. 

Description. — Shell  elongate,  compressed,  inequilateral,  highest  in  front  of  the 
umbones,  tapering  posteriorly.  Anterior  margin  rounded.  Urabones  incon- 
spicuous, with  a  carina  extending  to  the  postei'ior  extremity.  A  very  shallow 
siilcus  passes  from  the  umbo  obliquely  forwards  across  the  valve.  In  front  of  this 
sulcus  the  ornamentation  consists  of  narrow,  sharp,  concentric  ribs  separated  by 
broad  interspaces  ;  both  ribs  and  interspaces  are  crossed  by  numerous  radial  rows  of 
very  small  pointed  projections.  Behind  the  sulcus  the  concentric  riljs  become  less 
distinct  or  represented  by  growth-rings  only. 

Affinities. — This  species  is  allied  to  A.  (Cercomya)  Bohinahliua,  d'Orbignj-,'  but 
the  posterior  pai"t  of  the  shell  is  more  elongate. 

Bemarl's. — I  have  seen  only  three  examples  of  this  species.  Pictet  and 
Campiche  state  that  the  part  of  the  shell  just  in  front  of  the  carina  is  ornamented 
with  radial  rows  of  punctate  striae ;  these  are  not  seen  on  the  English  specimens,  pro- 
bably on  account  of  their  somewhat  imperfect  preservation.  One  of  our  specimens' 
(Plate  XXXIX,  fig.  3)  agrees  very  closely,  both  in  the  form  of  the  .shell  and  in  the 
character  of  the  ornamentation,  with  the  figure  given  by  Pictet  and  Renevier;  the 
others  (figs.  2,  4)  approach  more  nearl_y  the  examples  figured  Ky  Pictet  and 
Campiche,  but  the  anterioi*  part  of  the  shell  is  rather  higher. 

Tupe. — From  the  Aptian  of  the  Pcrte-du-Rlione. 

Distrilmtion. — Lower  Greensand  (Crackers)  of  Atherfield. 


Anatixa  (Cercomya),  sp.     Plate  XXXIX,  fig.  oa,  h. 

Description. — Shell  very  long,  compressed,  considerably  inequilateral,  highest 
in  front  of  the  umbones;  posterior  \r,\v\  tapering,  and  curved  upwards.  Anterior 
margin  rounded;  venti-d  niai'gin  convex;  pcstero-dorsal  margin  concave.  Um- 
bones curved  posteriorly,  with   a  carina  and  a    shallow  furrow  extending  to  the 

1  '  Pal.  Franc.  Terr.  Crct.,'  vol.  iii  (1845),  p.  374,  pi.  ccclxx,  figs.  6—8. 


240  CRETACEOUS    LAMELLIBRANCHIA. 

postei-iiir  I'-xtrt'iuity.  On  the  anti'i'ior  part  of  the  sIil'U  the  (ii'iiaiiieutatiuii  consists 
of  narrow,  sliarp,  concentric  ribs,  ■\vliicli  become  less  distinct  on  the  median  and 
posterior  parts. 

Bemiiiis. — Only  one  specimen — an  internal  cast — has  been  seen.  Tt  i-esembles 
A.  (Gercumija)  riii.ri/ifl>i,  but  is  more  inequilateral  and  more  elongate. 

DistriJjutioii. — Upper  Greensand  of  the  Isle  of  Wight. 

Anatixa  (Ckkcomya),  sp.     Plate  XXXIX,  fig.  C. 

Imperfect  specimens  of  a  species  of  Anatina  {Gercomya)  have  been  found  in  the 
Upper  Greensand  of  Warminster  and  in  the  Cenomanian  (Bed  10)  of  Dunscombe, 
South  Devon.     In  shape  they  resemble  A.  {Gercomya)  fvoiliirtu,  Zittel.^ 

Genus — Thuacia,  Leach  in  //.  M.  1).  de  Blaiiivilh',  1824. 
('  Diet.  Sci.  nat.,'  vol.  xxxii,  p.  347.) 

Thhacia  PuiLLiPsi,  lidmer,  1841.     Plate  XXXIX,  figs.  7— U. 

1829.     Mya  depressa,  J.  Phillips.    Geol.  Yorks.,  p.  121,  pi.  ii,  fit;.  8  (uou  M.  depressa, 

Sowerbv,  1823). 
1841.     Thracia  FHihhipsii,  F.  a.  Bljmer.     Die  Versteiu.  d.  uord-deutsch.  Kreide- 

geb.,  p.  74,  pi.  X,  fig.  1. 
1850.  —         RBCVRVA,  A.  (VOrhiijiiy.     Prodr.  de  Pal.,  vol.  ii.  p.  117.     {'f  T.  snb- 

(lepressa,  p.  74.) 
1854.  —         Phillipsi,  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  227. 

1865.  —  —         F.J.PictetamlG.Gampiche.    Foss.  Terr.  CrJt.  Ste.  Croix 

(Mater.  Pal.  Suisse,  ser.  4),  p.  120. 
—  —         EECURVA,  Picfet  and  Ganqnche.     Ibid.,  p.  120. 

1870.  —  —        F.  Stoliczka.     Palaeont.  ludica,  Cret.  Fauua  S.  India, 

vol.  iii,  p.  72  {Corimya  V). 
1875.  —         Phillipsii,  Phillips.     Op.  cit,,  ed.  3,  p.  254,  pi.  ii,  fig  8. 

1900.  —         Phillipsi,  A.  Wdllemann.      Die  Biv.   u.  Gastrop.  d.  deutscli.  u. 

liolliind.   Neoeoms   (Abliaudl.  d. 
k.  preussisoli.  geol.  Land.,  n.  f., 
pt.  31),  p.  139,  pi.  vi,  fig.  6. 
1905.  —  —         E.  Harborf.     Die   Faima   d.    Seliauiuburg-Lippe"sclien 

Ivreidemulde  (ibid.,  pt.  45),  p.  77. 
1908.  —  —         WoUemaiiH.     Jalirb.   d.   k.  preuss.    geol.    Laudesaust., 

fiir  1908,  vol.  xxix,  p.  16tj. 

Description. — Shell  thin,  more  or  less  ovate  in  outline,  moderately  convex,  the 
right  valve  a  little  more  convex  than  the  left,  slightly  inequilateral.     Antero-dorsal 

1  '  Die  Bivalv.  d.  Gosaugeb,,'  pt.  1  (1864),  p.  10  [114],  pi.  i,  fig.  6. 


THRACIA.  241 

margin  nearly  straight,  Avitli  a  considerable  ventral  slojie  ;  anterior  margin  rounded, 
passing  gradually  into  the  convex  ventral  margin  ;  posterior  margin  rather  short, 
oblique,  more  or  less  truncated,  forming  a  rounded  angle  with  the  nearly  straight 
and  veutrally  sloping  postero-dorsal  margin.  Umbones  rather  prominent,  curved 
inwards  and  slightl_v  backwards.  Postero-dorsal  part  of  valves  cduipresseil,  some- 
times with  a  small  cariiui.  Surface  with  numerous  small  concentric  growth-ridges. 
Measiir<'inenfti  .■ 

(1)  (2)  (3) 

Length  .  68         .         64         .         VJ  mm. 

Height  .  52         .         4(i         .         :38    „ 

Thickness  .  30         .         28         .         22    „ 

(1—3)  Speetou. 
Affinities. — It    is    probable,  as  maintained    by  Harbort,'   that  Thracia  striata, 
Weerth,-  is  not  specifically  distinct  from  7'.  I'liillipsi. 

Bemarls. — The  greater  part  of  the  shell  has  disappeared  from  most  of  the 
examples  found  at  Speetou,  and  usuall}-  some  part  of  the  margin  of  the  cast  has 
also  been  lost.  I  have  not  seen  sufficient  examples  to  enable  me  to  determine 
whether  the  variation  of  this  species  in  England  is  as  great  as  in  the  case  of  the 
specimens  found  in  Schaumburg-Lippe  and  described  by  Harbort. 
Ti/jte. — From  Speetou,  in  the  York  Museum. 
Distribution. — Speetou  Clay  (zone  of  Belemnites  Jacitlnm)  of  Speeton. 

Tiii;\ciA  ROTUNDATA  (So^vrA//),  18:56.     Plate  XXXIX,  fig.  M).i,b. 

1836.     Panop^a  ROTUNDATA,  /.  de  C.  Soirerhij.     Traus.  Geol.  Soc,  ser.  2,  vol.  iv, 

■  pp.  129,  337,  pi.  xiu,  fig.  2. 
1850.     Lyonsia  sdbbotundata,  A.  trOrbUjnij.     Prodr.  de  Pal.,  vol.  ii,  p.  74. 
1854.     Myacites  eotundata,  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2.  p.  214. 
1865.     Thracia  subrotundata,  F.  J.  Pirtct  and  G.  Cnnqiiche.     Foss.   Terr.   Cret. 

Ste.  Ci-oix  (Mat'.'r.  Pal.  Suisse,  ser.  4),  p.  120. 
1870.     CoRiMYA  ROTUNDATA,  F.  Sloliczlca.     Palscout.  Iiulioa,  Cret.  Faima  S.  ludia, 

vol.  iii,  p.  72. 

Description. — Shell  regularly  convex,  oval,  slightly  iuc'(|uivalv('  and  iniMpiilateval. 
Anterior  an<l  ventral  margins  convex,  forming  a  regular  curve.  Dorsal  part  of 
posterior  margin  ol)lique,  forming  an  angle  with  the  ventral  part.  Umbones  broad, 
in  contact,  with  a  narrow,  sharp,  curved  carina  extending  to  tlie  posterior  angle 
and  limiting  a  triangular,  concave,  postero-dorsal  area,  which  is  ornamented  with 
fine  ribs  running  parallel  to  the  posterior  margin.  Sides  of  valves  with  similar 
ribs  extending  in  a  radial  direction. 

^  'Die  Fauna  d.  Schauiiiburj.c-Lippe'sclieu  Kreideuiulde '  (1905),  p.  78. 

=  'Neocomsundst.  im  Teutolmrg.  Waldo"  ('Pala-ont.  Aliliaiidl. '  II,  1884),  p.  40,  pi.  viii.  fii,'.  10. 
Wollemaun, '  Die  Bivalv.  u.  Gastrop.  d.  deutsoli.  n.  liolliiud.  NeoL-oins  '  (1900),  p.  1 40,  pi.  vii,  fig.  1. 

32 


(1) 

(2) 

40 

32  iiini. 

32 

07 

-J'     „ 

oo 

17 

242  CRETACEOUS    LAMELLIBRANCHIA. 

Measurements  : 

Length 
Height 
Tliickness  .  . 

(1.  L* )  Lviujilie. 

Affinities. — This  species  is  allied  to  T.  rutinul't,  J^ictet  iuid  Roux,'  from  the 
Gaiilt  of  the  Perte-du-Rhune  and  Sainte  Croix,  Ijut  is  distinguished  by  its  more 
rounded  outline,  smaller  postero-dorsal  area,  and  less  distinct  concentric  ornament. 
It  is  also  allied  to  T.  carinifern  (p.  244). 

Bemarls. — Two  internal  casts  of  this  species  from  Lympne  are  in  the  Museum 
of  Practical  Geology  (23470,  23471) ;  the  larger  agrees  closely  with  Sowerby's 
figure,  and  may  perhaps  be  the  type,  but  the  locality  given  by  Sowerby  is  Court- 
at-Street,  1^^  miles  west  of  Lympne.  A  small,  somewhat  crushed  example  from 
the  Atherfield  Clay  at  Dover  colliery  probably  l)eIongs  to  this  species.  No  other 
specimens  have  been  seen.  The  specimens  recorded  by  Topley  as  7'.  riiriinfcrn 
probably  belong  to  T.  rotiinJata. 

Disfriliiitioii. — Hythe  Beds  of  Lympne  and  Court-at-8treet.- 

TuKAi'iA  RoiiiNALDiXA  r  {(V Orhiijii i/),  1845.     Plate  XL,  figs.  1 — 3. 

Descri2)tioii. — Shell  oval,  nearly  equilateral ;  I'ight  valve  more  convex  than 
the  left;  posterior  part  not  (juite  so  high  as  tlie  anterior  part ;  postero-dorsal  \)avt 
compressed.  Anterior  margin  rounded;  ventral  margin  moderately  convex; 
posterior  margin  slightly  curved  ;  postero-dorsal  margin  nearly  straight.  Umbones 
rather  prominent,  curved  posteriorly.     Surface  smooth,  except  for  growth-lines. 

Measurements  : 


Length 
Height 
Breadth 


(1) 

(2) 

(3^ 

36 

26 

15   mm. 

23 

17 

0     „ 

13 

10 

c.    „ 

(1)  Penia-hed.  (2,  3)  Crackers,  Atherfield. 


Remarls. — In  the  English  specimens,  which  are  here  provisionally  referred  to- 
T.  h'iihlniikliiHi,  the  shell  is  jireserved,  but  the  examples  of  that  species  figured  l)y 
d'()i'l)igny^  and  by  Pictet  and  Campiche'  are  internal  casts,  and  it  is  consequently 

'  '  Moll.  Foss.  Grcs  verts  de  Greucve '  (1852),  p.  414,  pi.  x.xix,  fii,'.  (3.  Pictet  and  Campiche,  '  Foss. 
Terr.  Cret.  Ste.  Croix'  ('Mater.  Pal.  Suisse,'  ser.  4,  1865),  p.  117. 

-  Thracia  Nieoleti  (Agassiz)  has  been  recorded  by  Morris  and  by  Topley  Iroiu  the  Hythe  Beds  of 
Hythe,  but  I  have  not  seen  any  British  examples  of  that  species. 

3  '  Pal.  Frau9.  Terr.  Crct.,'  vol.  ili  (1845),  p.  380,  pi.  ceclxxii,  figs.  1,  2. 

■'  'Foss.  Terr.  Crct.  Ste.  Croix'  ('Mater.  Pal.  Suisse,'  ser.  4,  1865),  p.  114,  pi.  cviii,  figs.  5,  6. 


THRACIA.  243 

(lifRcult.  especially  without  the  opportunity  of  comparing  specimens,  to  establisli 
the  identification.  Professor  Boule  informs  me  that  the  type  is  a  poorly  preserved 
specimen,  but  that  its  outline  is  satisfactorily  represented  in  (rOi'bio-ny's  fio-ure; 
the  specimen  is  now  in  tJie  Natural  History  Museum,  Paris.  T.  Iu>huuihlina  is 
allied  to  T.  mocomiensls  (d'Orbigny),'  but  is  said  to  differ  from  tlic  latter  l)y  the 
greater  curvature  of  the  ventral  margin  and  by  its  relatively  sliorter  shell. 

Distrihatiou, — Lower  Greensand  (7V/;/r(-l)cd  and  Crackers)  of  Atherfield. 
Atherfield  Reds  of  Redhill,  Reigate. 

'i'iii;A('iA  Sano'X\e-Crucis,  ridet  civd  Cdnqiirln-,  18()5.      Plate  XL,  tigs.  4 (i. 

1865.     Thracia  SANCTiE-CRrcis,  F.  J.  Pirli^t  ami  G.  Campirh,-.     Foss.  Terr.  Crot. 

Ste.  Croix  (Mater.  Pal.  Suisse,  ser.  4), 
p.  117,  pi.  cviii,  fio-.  8. 

1870.  —  —  F.  Stoliczht.     Palseont.    Iiulica,   Cret.   Fauna  S. 

India,  vol.  ill.  p.  72. 

Description.  —  Shell     oblong,     compressed,     inequilateral.        Anterior     margin 

rounded;    ventral   mai'gin   slightly   curved;    posterior   margin   truncated,   slightly 

convex,  forming  an  angle  with  the  postero-dor.sal  margin.     A  carina  e.xtends  in  a 

curve  from  the  umbo  to  the  postero-ventral  angle  and  cuts  off  a  concave  postero- 

dorsal  area.      The  surface  of  the  shell  is  ornamented  with  growtli-rings. 

Measurements  : 

(1)  (-') 

Length  .  .  43  .  3'.)   mm. 

Height  .  .  20         .  Ki     „ 

(1)  Gault,  Folkestone. 

(2)  Gault,  Black  Veu. 

Aijiuih'ea. — It  seems  doubtful  whethei-  this  species  is  distinct  from  2\  siviplex 
(d'Orbigny),  of  which  casts  only  are  figured  by  d'Orbigny-  and  by  Pictet 
and  Campiche^;  but  the  latter  authors  state  that  it  differs  from  T.  siuqilcr  by  the 
absence  of  an  internal  rib,  the  })resence  of  a  carina,  and  by  the  more  acuminate 
anterior  end. 

Ti/jye. — From  the  LTpper  Gault  of  Ste.  ('roi.\. 

I >isti'iliiiti(iii. —  Gault  of  Folkestone  and  iJlack  ^'en. 

Tiii;.\(iA,  sp.      i'late  .\l>,  figs.  7 — '.». 

Some  examples  of  Tlinicia,  usually  of  rather  large  size,  apjiear  at  first  .sight  to 
be  distinct  from  T.  Smicfie-Gritcis  on  account  of  their  i-elatively  greater  height  and 

1  'Pal.  Frane.  Terr.  Cri't.,'  vol.  iii  (1845),  p.  381,  pi.  cei-lxxii,  fi>.;s.  3,  4.  Pictet  aud  Cauipiche, 
op.  cit.,  p.  11-5,  pi.  cviii,  fij^s.  3,  4. 

-  Op.  cit.,  p.  382,  pi.  ecelxxii.  flip's.  .5,  ti. 

8  '  Foss.  Terr.  Crc't.  Ste.  Croix  "  ('  Mater.  Pal.  Suisse,'  ser.  4,  1865),  p.  116,  pi.  iviii.  fii;.  7. 


2U  CRETACEOUS    LAMELLIBRANCHIA. 

less  distinct  carina.  When,  however,  a  consideral)le  nunil)er  of  specimens  are 
compared  it  is  difficult  to  draw  any  line  of  separation  between  these  forms  and  T. 
Sanctse-Crucis.  But  since,  in  most  cases,  the  original  shape  of  the  shell  has  been 
more  or  less  considerably  modified  l)y  pressure,  it  is  not  easy  to  come  to  a  definite 
conclusion  in  this  matter;  moreover,  in  botli  7'.  Sa)ictas-Grucis  and  the  larger  forms 
there  is  clearly  some  variation  in  relative  heii^'lit  and  length  of  the  sliells,  and  in 
the  distinctness  of  the  carina.^ 

JJistribidio)!. — Gault    of   Black    Yen    and    Folkestone.      Upper   Greensand   of 
Blackdowu  and  Devizes. 


Thracia  CARiNiFEifA  {Soivevhi/),  182().     Plate  XL,  figs.  10 — 13. 

182(j.     LuTEARiA  r   CAEiNiFERA,  /.  lie  C.  Soivefhy.     Mill.  C'oiuli.,   vol.  vi,  p.  66,  pi. 

dxxxiv,  fig.  2. 
1832.  • —  —A.    Passij.       DescTipt.    gi'ol.    tie   la   Seiue-Iiift'r., 

Atliis,  \>.  6,  pi.  xiii,  figs.  6,  7. 
1842.     CoBiMYA  CARINIFEKA.  L.  Ayassiz.     Etudes  crit.  Moll.  Foss.,  Myes,  p.  264. 
1845.     Lyonsia  carinifera,  A.  d'Orhiijni/.     Pal.  Franc.  Terr.  Crct.,  vol.  iii.  p.  385, 

pi.  eeelxxiii,  figs.  1,  2. 
1850.  —  —A.  cVOrblijiiy.     Prodr.  de  Pal.,  vol.  ii,  p.  158. 

1852.  —  —  A'.  Ktier.     Deukschr.  d.  k.  Akad.  d.  Wisseiiscli.  Wien, 

Math.-uat.  CI.,  vol.  iii.  p.  311. 
1854.     LuTEARiA  CARINIFERA,  /.  Morfis.    Cat.  Brit.  Foss.,  ed.  2,  p.  208  (r  Thracia). 
1865.     Thracia  carinifeka,  F.  J.  Pictet  aitd  G.  Campiche.     Foss.  Terr.  Cret.  Ste. 

Croix  (Mati'r.  Pal.  Suisse,  ser.  4),  p.  121. 
1870.  —  —  F.  Sfuliczht.     Palaeout.  ludiea,  Cret.  Fauua  S.  ludia, 

vol.  iii,  p.  72. 
1893.     Lyonsia  carinifera,  .4.  Fc(7i?(7i.    Stud.  imGebietederbiJhru.  Kreideformat. 

V.  Prieseii.  Si-liiclit.,  p.  97,  fig.  115. 

Description. — Shell  thin,  oval,  of  moderate  cunve.xity,  slightly  inequivalve  and 
inequilateral.  Anterior  margin  rounded,  jjassing  gradually  into  the  reguhirly 
convex  ventral  margin.  Posterior  margin  truncated,  straight  or  slightly  concave. 
Postero-dorsal  margin  nearly  straight.  Umbones  In'oad,  incurved  close  together, 
with  a  sharp  carina  passing  to  the  postero-ventral  angle  and  limiting  a  flattened 
or  slightly  concave  postero-dorsal  area,  whieh  is  tlivided  in  the  middle  l)y  a  shallow, 
longitudinal  fnri'ow.  -lust  in  front  of  the  carina  is  a  broad,  shallow,  concave 
depression. 

Ornamentation  consists  of  broad,  slightly  raised,  concentric  folds  Avhich  are 
more  distinct  on  the  anterior  part  than  elsewhere.     On  the  postero-dorsal  area  are 

^  A  similar  case  of  distortion  and  variation  is  i'urnislied  liv  Thracia  semijilanata,  Whiteaves, 
'  Mesozoie  Foss.'  ('  Geol.  Surv.  Canada'),  vol.  i  (1884),  p.  221,  pi.  xxix,  fig.  5. 


PHOLADOMYA.  245 

nimiorous,  fine,  regular  ribs  parallel  with  the  posterior  margin  ;  on  the  remainder 
of  the  shell  similar  ribs,  but  running  in  a  radial  direction,  occui-. 
Measurements : 

(1)  (2)  (3)  (4) 

Length  .         .         37         .         88         .         30         .         20  mm. 
Height   .         .         23         .         22         .         21         .         1-t     ., 
Thickness       .         15         .         14         .         —         .         10     „ 

(1)  Chalk  Marl,  Chard. 
(2,  4)  Chloritic  Marl,  Devizes. 
(3)  Chalk  Marl,  Ventiior. 

Abilities.— In  this  species  the  shell  is  more  elongate  and  less  convex,  the  carina 
more  prominent,  and  the  postero-dorsal  area  larger  than  in  T.  mf  inula  fa  (p.  241). 
T.  carinifera  is  closely  allied  to  T.  I'lcgmis  (d'Orbigny),'  froni  the  Cenomanian  of 
St.  Sauveur,  l)ut  is  less  elongate.  T.  German  (Greinitz)-  from  the  Senonian,  is 
regarded  by  Bi-auns'^  as  a  synonym  of  T.  carinifera  ;  but  without  seeing  specimens 
of  the  former  it  is  ditlicult  to  express  an  opinion  of  its  relationship. 

licmarls. — The  specimens  vary  considerably  in  the  pro])ortion  of  leiigtli  to 
height,  but  in  some  cases  the  differences  are  probably  due  partly  to  crushing. 
The  shell  itself  is  seldom  preserved. 

Type. — The  type  came  from  the  Cenomanian  of  Dowlands  (South  Devon)  and 
was  originally  in  the  collection  of  Sir  H.  T.  De  la  Beclie,  but  cannot  now  l)e 
found. 

Distribution. — Chloi'itic  Marl  of  Devizes  and  Maiden  Bradley.  Chalk  .Marl  of 
Veutnor,  Evershot,  and  Chard. 


i^am%— PHOLADOM YJ D^¥.,  (Iraij. 

Genus — Puoi-.viH>MY.\,  (/.  B.  Soice,ii/,  1825. 
('  Genera  Eee.  ami  Foss.  Shells,'  uo.  xix,  pi.  .x.xxvii.) 

Phol.\.domv.v  Cok.nuki.iax.v  {(VOrliiij)iii),  1844.     Plate  XLT,  figs.  2'/,//,  '■\. 

1844.  Cabdium  CouNUELiANUJi,  A.  d'Oihi(jiiij.     I'al.   Frauc.  IVrr.   Crt't.,  vol.   iii, 

p.  23,  pi.  cclvi,  figs.  1,  2. 

1845.  —  —  E.  Forbex.     Quart.  Jourii.  Greol.  Soc,  vol.  i,  p.  243. 
1850.     Pholadomya  Cornueliana,  A.  crOrhiijiiy.     Prodr.  ile  Pal.,  vol.  ii,  p.  117. 
1854.     Cardium  Cornuelianum,  /.  Morris.     Cat.  Brit.  Foss  ,  ed.  2,  p.  192. 


1  'Pal.  Fran9.  Terr.  Crct.,'  vol.  iii  (1845),  p.  386,  pi.  ccclxxiii,  figs.  3 — 5. 
-  '  Quaiiersandst.  oder  Kreidegeb.  in  Deutschlaud  '  (1850),  p.  150,  pi.  x,  figs.  9 — 11. 
*  '  Seuon.  Mergel  d.  Salzberges,'  Zeit.schr.  f.  d.  gesammt.  Naturwiss.,  vol.  xlvi  (1876).  p.  35!'.  pi.  x, 
figs.  18,  19. 


246  CRETACEOUS    J.AMELLTBRAXCHIA. 

18o5.     Pholadomya  Cornueliana,  F.  J.  Pirtet  and  E.  Renevier.   Foss.  Terr.  Ajitieu 

(Mati'r.  Pill.  Suisse,  ser.  1),  p.  59,  pi.  vi,  fi>;.  6. 
1865.  —  —  F.J.PictetandG.Campiche.     Foss.  Terr.  Grot. 

Ste.  Croix  (Mater.  Pal.  Suisse,  ser.  4),  p.  87. 
—  —  —  H.  Coquaiul.     Aptien  de  I'Espague,  p.  93. 

1870.  —  —  F.  Sloliczka.     Palsont.  ludica,  Cret.  Fauua  S. 

Imlia,  vol.  iii,  p.  75. 
1875.  —  —  G.Moesch.    Mou.  PliolacIom_ven,p.  96,  pi.  x.xxiii, 

fig.  8  (ypl.  xxxvi,  fig.  4). 

iJi'scriptioi). — Shell  .small,  .sliurt,  oval,  inflated,  conijiressed  posteriorly, 
moderately  ine([uilateral  with  a  small  gape  at  the  posterior  end.  Margins  rounded. 
Umbones  prumiiient,  incurved. 

Ornamentation  consists  of  strong,  ronndcd,  radial  I'ibs.       The  grooves  between 

the  i'il)s  are  shallow,  and  broader  than  the  ribs.     Concentric  riljs  cross  the  grooves 

and  ribs,  giving  to  the  latter  a  granulate  or  tuberculate   api)ea)'ance.     Near  tlie 

posterior  and  anterior  mai-gins  radial  ribs  are  absent. 

Mc(t!inri')iU'iifs  : 

0)  (2) 

Length  .  .  20  .    .  1:1  mm. 

Height  .  .  10  .  K)     „ 

(1,  2)  Atherfieia. 
Ajji iiitii'K. — This   species   reseml)les   P.  Saurtl-SdJix  (Rdmer)'    from    Texas   and 
/'.    ]'iij)tP!<i,   Lartet,'-    from     I'alestine,    Syria,    and    Zululand,    and    1'.   siilxliiuni.'^i.i 
(d'Orl)igny),'^  from   the  ( 'enomanian  of  Le  Mans. 

7'///>e. — From  the  Aptian  of  Was.sy  (Hante-Marne). 

Dtstribtttloii. — jjower  (Jreensand  (Crackers)  of  Atliertield.  Recorded  by  Topiey 
from  the  Atherfield  Beds  of  Peasemar.sli  and  Shalford. 

i'lKH.AiioMVA  (MCAxri-A  {S<Hr>'rhi/),  IS'Ml      i'late  XL,  tig.  11;    Plate  XLl,  fig.  1. 

1708.     C.  N.  LatKj,  Hist,  lapidum  tiguratonmi,  p.  146,  pi.  xliv,  tig.  1. 
1718.     J.  J.  Scheuchzer,  Helvetiae  hist,  uat.,  pt.  3,  p.  307,  fig.  113. 
1742.     L.  Bourguet,  Traitc  des  Petrific,  pi.  xxiv,  fig.  145. 


1  •  Kri'idfliilil.  V.  Texas'  (1852),  p.  48,  pi.  vi,  fig.  7.  F.  CormifJiana  has  heeu  compared  with 
Corbiihi  wquivalvU,  Cxoldfuss,  by  Pictet  and  Reuevier,  Pictet  and  Campit-he,  and  Moesoh,  but  HolzaptVl 
has  shown  that  Goldfuss'  species  belongs  to  the  genus  LiopiMa.  Holzapi'el,  '  Die  MoUusk.  Aicheu. 
Kreide  '  ('  Palseontographica,'  vol.  xxxv,  1889),  p.  150,  pi.  ix,  figs.  4 — 6;  Miiller,  '  Mollusk.  d.  Untersenon 
v.  Braunschweig  u.  Ilsede '  (1898),  p.  76,  pi.  x,  fig.  9. 

-  'Explor.  gcol.  de  la  Mer  Morte '  (1877),  p.  126,  pi.  xi,  fig.  9;  BlancUenhorn,  ■  Beitr.  z.  Geol. 
Syriens'  (1890),  p.  94,  pi.  v,  figs.  14—17;  Kossmat,  '  Deukschr.  d.  k.  Akad.  Wiss.,  Wien,'  vol.  Ixxi 
(1902),  p.  55,  pi.  iv,  fig.  9  ;  Newton,  ■  Trans.  Roy.  Soc.  S.  Africa,'  vol.  i  ( 1909),  p  79,  pi.  vi,  figs.  3—6. 

•'  '  Pal.  Franc.  Terr.  Cret.,'  vol.  iii  (1844),  p.  38,  pi.  eel.  figs.  1—3.  An  internal  east  resembling 
P.  t^iiliiliiieiisiK  has  been  found  by  Mr.  J.  Scaues  in  the  C'hloritic  Marl  of  Maiden  Bradley. 


PHOLADOMYA.  347 

1836.     PHO.AS  OXC......S,  /.  ,e  C.  So..erl,j.     Trans.  Geol.  Soc.  ser.  2.  vol.  iv.  ,,,. 

184.0      T3  130,  338.  pi.  xvi,  fij;.  1. 

1840.     PHO...OM..  ..o.o.r.,A.  G.Iclf.ss.     Pefof.    Genu.,    vol.   ,i.  p.  27U.  pi. 

1840  __  >^^^''''  fig-  3- 

~  ^-^'J^^^tz.     fitudes  crit.  M„ll.  Foss.,  Myes,  p.  57, 
pi.  i.  fit,'s.  IC.  17. 

-  SCHEUCHZERI,  Aya,,h.      lhh\.,  p.  .58,  p|.  iil.  fi.s.  3-  7,  pi.  iiil 

%'■  7. 

—  Favrina,  .'(j/a.v.s/r.     Iliid.,  p.  .59,  pi.  iil,  fi^,,s.  1,  2. 

-  -  L.VNGII,  To//.,  i„  Z,.y„,,,,v.     Mem.  Soc.  gJol.de  France,  ser.  2, 

1845  '■"'•  ''•  P-  24- 

ELONGATA,  ^.  ,rO,i/,/„^.     Pal.   Franc.  Terr.   Cret.,   vol.   iii, 

_  p.  350,  pi.  ccclxii. 

lo,n  GiOANTEA,  E.  Forbes.     Quart   Jouru.  Geol.  Soc,  vol.  i,  p.  238 

180U.  _  ELONGATA,  cWrbiyny.     Prodr.  de  Pal.,  vol.  ii,  p   73 

Faveina,  F.  J.  Pictet  „,ul  W.  Bo,u:     Moll.  Foss.  Gr^-s  verts 
10.A.  '^''  Geneve,  pp.  403,  546,  pi.  xxix.  fijr.  1 

l«?t  ~  «i«ANTEA.  /.  3I„n-h.     Cat.  Brit.  Foss.,  ed.  2,  p   ooq 

_  ~  ELONGATA.  G.  CW.„„.     Moll.  Foss.  de  ITonne.  p.  55. 

—  F.  J.  Pictet  a„(l  E.  Renevier.     Foss.   Terr.  Aptieu 
185g                _  ,  (Mater.  Pal.  Suis.se,  ser.  1),  p.  61. 

—  J.rUaiwva.y.Piera.   Mem.geog.-agric.  de  Castellon. 

1861  -_  ^'''  "''  ^°-  ^*'- 

1864— or        _  ~         P-de  Loriol.  Anim.  Invert.  Foss.  Mt.  Sali-ve,  p.  56. 

~  ~         F-J-Pi<-tetan(lG.Camiiiche.    Foss.  Terr.  Crt't.  Ste. 

Croix  (Mater.  Pal.  Suisse,  ser.  4), 

lr.7A  !'•    ""*■  P'-   ^■''■'   fi^'**-    1— *• 

-  GiGANTEA  et  ELONGATA,  F  Stoliczka.     Pateont.  Indica,  Cret. 

-loyt-  Fauna  S.  India,  vol.  iii,  p.  7f. 

^^-  ~  GIGANTEA,  C.  Moescli .     Mon.  Pholadoniyen,  p.  82,  pi  xxx.  fig. 


6  :  pi.  xxxi,  figs.  2- 

1»»4.  _  cf.  GIGANTEA,  0.  Wcnth.     Die  Fauna  des  Neoeoni.  im  Teuto- 

burg.  Walde  (Palaeout.  Abhandl.,  vol.  ii), 
P- 34,  pi.  viii,  figs.  2,  3. 
^^^-  ~  Weerthii,  F.  Vocjel     Hollaudiseli.  Kreide.  p.  5H. 

—  —  ELONGATA.  G.  Maa,.      Zeifsehr.    d.   deutsch.  geol.   GesellscL.. 

~  —         -A-  Wollemaiu,.     Ibid.,  vol.  xlviii.  n  850 

~  —         ^.  TFo/?e»(((««.     Die  Biv.  u.  Gastrop.  d.  deutsch. 

u.  holliiud.  Neoconis  (Abliaudl. 
d.  k.  preussiscli.  geol.   Laud., 
N.  F.,  pt.  31),  p.  133 
~  ~  —         G.  Mailer.     Deutscli-Ost-Afrika,  vol.   vii,  p.  557, 

1>1.  xxi,  fig.  1. 
^^^^-  ~  ~         G.  Binchhavilt.     Palipontographica,   vol.   1,   ],.    7.;. 

pi.  XV,  figs.  1,  2. 

*^'^'  ~  —A.  Stojanoff.     Ann.  gc'ol.  et  niin.  de  la  Eussie,  vol. 

X,  p.   111). 


248  CRETACEOUS    LAMELLIBRANCHIA. 

Description. — Sliell  large,  eloniifate,  some  what  arched,  convex,  l)ut  with  tlie  sides 
of  the  posterior  part  more  or  less  flattened,  very  ine(|uilateral,  with  a  large  gape 
at  the  posterior  end.  Anterior  part  short,  with  a  rounded  margin.  Venti'al  margin 
curved.  Posterior  margin  sul)truncate,  roiuukcl.  Po.stero-dorsal  margin  long, 
slightly  concave  or  almost  straight.  Umbones  broad.  Near  the  nnd)ones  the 
antero-dorsal  and  postero-dorsal  marginal  parts  of  the  shell  are  depressed. 

Ornamentation  consists  of  numerous  narrow,  sharp,  prominent  and  sometimes 
slightlj-  serrate  radial  ribs,  which  are  straight  or  slightly  curved.  Near  the 
anterior  and  the  postero-dorsal  mai-gins  ribs  are  absent ;  on  the  postero-dorsal  part 
of  the  shell  they  are  rather  inore  widely  separated  and  i-ather  more  jn-ominent 
than  on  the  median  ])art.  Between  the  ribs  are  broad,  concave  fun-ows  wliicli  aie 
crossed  by  numerous  growth-lines. 
Measiivfments  .• 

(1)  (2) 

Length  .  .  12()  .  122  mm. 

Height  .  .  63  .  GO    „ 

(1,  2)  Crackers,  Atlierfiekl. 

Jljiiiitirs. — The  elongate  form  and  numerous  sharp  ribs  distinguisli  tliis  from 
other  Cretaceous  species  of  Plioladomi/a. 

lii'niarls. — The  foreign  examples  of  this  species  show  considerable  vaiiatii)ii  in 
length,  in  the  curvature  of  the  shell,  and  in  the  nuiuber  of  ribs.  Some  of  the 
varieties  have  been  described  as  distinct  species,  but  Pictet  and  Campiche  have 
shown  that  there  are  numerous  transitions  between  the  different  varieties.  The 
English  examples  agree  in  most  cases  with  the  type  of  the  species,  but  some 
ajjproach  the  variety  described  by  Agassiz  as  P.  Scheuchzeri.  A  specimen  figured 
by  Moesch  shows  the  large  pallial  sinus. 

Ti/pe. — The  type  came  from  the  HytheBedsof  Court-at-Street,  but  cannot  now 
be  found. 

Distfibufioii. — Lower  Greensand  (Crackers)  of  Atherfield.  Atherfield  Beds  of 
East  Shalford.     Hythe  Beds  of  Court-at-Street  and  Lympne. 

Puor.AiioMVA  si'KKTONENSis,  sp.  uov.     Plate  XLT,  fig.  L',  A. 

Description. — Shell  large,  oval,  short,  intlated,  very  inecpiilateral.  Anterior 
margin  rounded;  ventral  margin  convex.     Umljones  broad,  incurved. 

Ornamentation  consists  of  numerous  (usually  about  twenty-one)  strong,  radial 
ribs,  separated  by  broad,  slightly  concave  interspaces.  Secondary  ribs  are  iiitru- 
duccd  at  a  short  distance  from  the  umbo,  and  usually  soon  become  as  large  as  the 
])riniary  ribs.  The  ribs  are  more  or  less  nodular.  Concentric  growth-lines  are 
present.  Two  or  three  of  the  anterior  ribs  are  more  widely  separated  than  the 
others.     On  the  postero-dorsal  and  the  anterior  parts  of  the  shell  ribs  are  absent. 


PHOLADOMYA.  249 

Affinities. — By  some  autliors  tliis  species  has  been  identified  with  P.  Martini, 
Forbes.  With  the  matevial  at  present  available  it  is  difficnlt  to  make  a  satisfactory 
comparison  ;  but  the  specimens  from  Speeton  are  of  considerably  larger  size,  with 
broader  and  less  prominent  nmbones,  and  with  the  posterior  part  of  the  shell  less 
compressed  than  in  P.  Martini. 

In  form  tliis  species  resembles  P.  alternans,  Roraer,'  l)ut  tlie  nmbones  are 
relatively  higher,  and  the  radial  ribs  more  numerous.  The  ribs  arc  not  so  numerous 
as  in  P.  Eherfi,  Wollemann." 

EemarJi:s. — The  specimens  from  the  clays  are  considerably  crushed,  whilst  in 
those  from  the  hard  nodular  beds  a  more  or  less  considerable  portion  of  the 
marginal  part  of  the  shell  is  missing. 

Difiribntion. — Speeton  Clay  (zones  of  Bclenmites  lateralli,  B.  jaculnni,  and  B. 
bnmsvicensis)  of  Speeton. 


PuoLAUO.MYA  M.vitTixi,  Forbc-^,  18-t-j.     Plate  XLI,  tig.  o. 

18i5.     Pholadomya  MiRxiNi,  E.  F.jrhe.-!.     Quart.  Jourii.  G-aol.  Soc,  vol.  i,  p.  233, 

pi.  ii,  fit;.  3. 
18-50.  —  —  A.  d'Orhhpi;/.     ProJr.  (le  Pal.,  vol.  ii,  p.  117. 

1854.  —  —J.  Morris.     Cat.  Brit.  Poss.,  ed.  2,  p.  220. 

1865.  —  —F.J.  Piclet  and  G.  Campiche.    Foss.  Terr.  Crct.  Ste. 

Croix  (Mater.  Pal.  Suisse,  ser.  4),  p.  92. 
?  1908.  —  —         A.  Wollemanii.     Jahrb.  d.  k.  preuss.  geol.  Laudes- 

anst.  fiir  1908,  vol.  xsix,  p.  165, 
pi.  X,  fig.  3. 

Description. — Shell  rather  small,  oval,  very  inequilateral,  anterior  part  inflated, 
posterior  part  compressed.  Unibones  prominent.  Escutcheon,  deep.  Ornamenta- 
tion consists  of  numerous  radial  riljs,  which  are  more  or  loss  tu))erculate,  and  ai-e 
more  widely  separated  anteriorly  than  on  the  median  part ;  on  the  anterior  and 
postero-dorsal  parts  ribs  are  indistinct  or  absent.  Concentric  ribs  and  growth-lines 
are  present. 

Remarks. — It  is  difficult  to  give  a  satisfactory  description  of  this  species,  since 
the  specimens  seen  are  few  in  uuiuber,  imperfectly  preserved,  and  usually  crushed. 
P.  Martini  appears  to  be  closely  allied  to  P.  Fahrimi,  d'Orbigny  (see  below).  It 
also  resembles  P.  hispanica,  Coquand."' 

1  Wollemaun,  '  Die  Biv.  u.  Gastrop.  <1.  dcutsch.  ii.  liolliimliscli.  Neocoms'  (1900),  p.  134,  pi.  v,  figs. 
9,  10  ;  pi.  vi,  tig.  3.  Speeiineus  with  fewer  ribs  from  the  Spilsin-  Saudstoue  aud  the  Claxbv  Ironstone 
of  Lincolnshire  approach  P.  alteniaiii  more  nearly  than  do  the  specimens  from  Speeton. 

2  Il)i.l.,  p.  136.  pi.  vi,  fig.  4. 

3  'Mou.  Aptien  de  I'Espague'  (1865),  p.  92,  pi.  vii,  figs.  5,  6. 

33 


250  CRETACEOUS    LAMELLIBRANCHIA. 

Type. — From  the  Hytlie  Beds  of  Piilborongli .  A  specimen  which  is  believed  to 
be  the  type,  but  wliich  is  more  crushed  dorso-ventrally  than  is  indicated  by  the 
figure,  is  in  the  Museum  of  the  Geological  Society  (No.  2197). 

Distribution. — Lower  Greensand  {Perna-heA  and  Crackers)  of  Atherfield. 
Hythe  Beds  of  Pnll)orough. 

Pholadomya  Fabuina,  (VOyhiijinj,  1845.     Plate  XLI,  fig.  G. 

1845.     Pholadomya  Fabrina,  A.  d'Orbiyny.     Pal.  Fran9.  Terr.  Crt't.,  vol.  iii,  \>. 

354,  pi.  ccclxiii,  figs.  6,  7.     (Non 
P.   Favrina,  Agassiz,  Pictet  and 
Roux.) 
1850.  —  —         d'Orbigny.     Prodr.  de  Pal,  vol.  ii,  p.  135. 

1865.  —  —         F.J.  Pictet  and  G.  Campiche.     Foss.  Terr.  Crct.  Ste. 

Croix  (Mak'r.  Pal.  Suisse,  ser.  4),  p.  92. 
1897.  —  Favbina?,  B.   B.  Newton.      Proc.  Dorset   Nat.    Hist,    aud 

Antiq.  Field  Club,  vol,  xviii, 
p.  92. 

?  Non  1874.  —  Fabbina,  C.  Moe.n-Ji.  Mon.  Pholadomyeu,  p.  94,  pi.  xxxii,  fig.  1. 

RemarJis. — Some  crushed  specimens  found  in  the  Gault  are  probably  examples 
of  P.  Fabrina,  d'Orbigny.  They  resemble  P.  Marti iii,  but  have  coarser  and  more 
distinctly  tiiberculate  ribs,  and  the  concentric  rings  appear  to  be  more  conspicuous. 

Distribution. — Gault  of  Black  Ven,  Okeford  Fitzpaine,  and  Folkestone. 

Pholadomya  decussata  (Muntell),  1S22.     Plate  XLI,  figs.  7—9;  Plate  XLII,  fig.  1. 

1822.     Cabdium  ?  DEcussATUM,  G.  Mantell.     Foss.  S.  Downs,  p.  126,  pi.  xxv,  fig.  3. 
1827.  —  —  /.  de  C.  Sou-erhy.     Miu.  Conch.,  vol.  vi,  p.  99,  pi. 

dlii,  fig.  1. 
1837.  —  —  A.  Gold/uss.     Petref.  Germ,  v.il.  ii,  p.  222,pl.  cxlv, 

fig.  2. 

—  Pholadomya  decussata,  G.  G.  Pitsc/i.     Polens  Paliiout.,  p.  87. 

1841.     Cardium  DECUSSATUM,    F.    A.    Rijmer.      Die    Versteiu.    d.    uord-deutsch. 

Kreidegeb.,  p.  71. 
1846.     Pholadomya  decussata,  A.  E.  Beuss.      Die  Verstein.  der  bohni.   Kreide- 

format.,  pt.  2,  p.  17. 
1850.  —  —  J.  de  C.  Sorverhy,'mF.  Dixon.    Geol.  Sussex,  p.  355 

(p.  385,  ed.  2),  pi.  xxix.  fig.  6. 

—  —  —  H.  B.Geiiiitz.    Das  Quadersaudst.  oder  Kreidegeb. 

in  Deutschlaud,  p.  146. 

—  —  —  J?.  Kiier.     Yerstein.  d.  Kreideniergels  v.  Leniberg 

(Haidinger's   Naturwiss.  Abhaudl., 
vol.  iii,  pt.  2),  p.  24. 


1869. 


1876. 


PHOLADOMYA.  251 

1850.     Pholadomya  decussata,  A.  AW,.      Geogu.-pateont.  Bescbreib.  v.  Lemberg 

(ibid.),  IX  236. 
^^^^-  ~  —J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  220. 

^^*'^-  —  —  var.  TRixaavhARiH,  H.  G.  Seeley.    Anu.Mag.Nat. 

Hist.,  ser.  3,  vol.  vii,  p.  122. 
1863.  —  (CARmvM.)DECvsaArA,  A.  v.Stromheck.     Zeitschr. der  deutscb. 

geol.  Gresellscb.,  vol.  xv,  p.  143. 
1865.  —  DECUSSATA,  F.  J.   Pictet  and  G.  Campiche.     Terr.  Cret.  Ste. 

Croix  (Matt'r.  Pal.  Suisse,  ser.  4),  p.  94. 
—  —         E.  Favre.     Moll.  Foss.  de  la  Craie  de  Lemberg, 

p.  106. 
1875.  —  _  A.  J.  Jukes-Browne.     Quart.  Joum.  Geol.  Soc, 

vol.  xxxi,  p.  300. 
~"  —  —  C  Moesch.     Mon.  Pboladomven,  p.  107,  pi.  xxxii, 

figs.  5  ?,  6  ;  pi.  xxxvi,  figs.  5,  6. 
—  D.  Brauns.     Zeitschr.  f.  d.  gesammt.  Natm-wiss., 

vol.  xlvi,  p.  361. 
?  1889.  —  _  j;.  Hohapfel.     Die  Mollusk.  Aacbeu.  Kreide  (Pal- 

eeoutographica,  vol.  xxxv),  p.  164, 
pi.  xiv,  figs.  3,  4. 
1891.  —  —  J.Buhm.     Kreidebildimg.    d.    Fiirbergs  u.   Sulz- 

bergs  (Palseoutograpbica,  vol.  xxxviii),  p.  73. 
1893.  —  —  A.  Fritsch.     Stud,  iiu  Gebiete  der  bolim.  Kreide- 

foi-mat.  V.  Prieseu.  Sebieht.,  p.  97,  fig.  116. 
?  1898.  —  —  G.  Mailer.    Mollusk.  d.  Uutersen.  v.  Brauuscbwei" 

u.  Ilsede,  p.  74,  pi.  x,  fig.  3. 
1^01.  —  —  A.  Wollemajin.     Jabrb.  d.  k.  preuss.  geol.  Laudes- 

aust.  fiir  1900,  vol.  xxi,  p.  22. 
1902.  —  --  A.  Wollemanit.     Liiueburg.  Kreide,  p.  79. 

Nou  1829.  —  —  /.  P},inq»<.     Geol.  Yorks.,  pp.  122,  186  (p.  255, 

ed.  3),  pi.  ii,  fig.  9. 

—  1842.  —  —  L.  Agassiz.     fitudes  crit.  Moll.  Foss.,  Myes,  p.  74, 

pi.  iv,  figs.  9, 10  ;  pi.  iv',  figs.  7 — 11. 

—  1843—50.    —  —  G.  P.  Desluiy:.-'.     Traitc  Ek'meut.  de  Couebyliol., 

vol.  i,  pt.  2,  p.  158,  pi.  V,  fig.  5. 

—  1849.  —  —A.  (VOrhhjntj.     Prodr.  de  Pal,  vol.  i,  p.  335. 

Distribution. — Shell  large,  inflated,  with  the  greatest  diameter  at  the  anterior 
end,  outline  .semi-ovate  (sometimes  sub-trigonal),  wedge-shaped  behind,  extremely 
inequilateral,  with  a  ^^nlall  posterior  gape;  height  and  length  often  nearly  equal. 
Ventral  margin  slightly  curved.  Posterior  margin  rounded.  Anterior  part  of  the 
shell  very  short,  flattened,  with  cordate  outline,  nearly  perpendicular  to  the  plane 
between  the  valves,  and  forming  almost  a  right  angle  with  the  sides  of  the  valves ; 
the  margin  of  the  anterior  part  is  more  or  less  angular,  and  just  within  is  a 
shallow  concave  part  parallel  to  the  margin,  whilst  the  median  part  is  convex,  and 


(1) 

(2) 

(3) 

98 

60 

54  mm 

74 

59 

52     „ 

65 

51 

49     „ 

252  CRETACEOUS    LAMELLIBRAXCHIA. 

that  near  the  umboiies  is  depressed.  Umboiies  curved  considerably  inwards  and 
more  or  less  forwards.     Escutcheon  depressed. 

Ornamentation  consists  of  narrow  I'adial  ribs  separated  hy  Itroad,  sliallow 
depressions.  Ribs  are  absent  from  the  posterior  part  of  the  shell,  and  from  the 
anterior  flattened  part,  except  near  its  margin ;  they  become  smaller  or  disappear 
altogether  near  the  ventral  margin.  "Well-marked  growth-rings  occur  over  the 
entire  surface  of  the  shell,  but  are  more  distinct  near  the  umbones  than  ventrally, 
and  give  a  granular  or  nodular  appearance  to  the  radial  I'ibs,  especially  on  the 
dorsal  part  of  the  shell. 

Measurements  : 

Length 
Height 
Thickness  . 

(1,  2)  Chalk  Marl,  Yeutuor. 
(3)  Clialk  Marl,  Eastbourne. 

Affinities. — The  smaller  forms  of  this  species  show  some  resemblance  to  i'. 
genevensis,  Pictet  and  Roux,^  from  the  Gault,  but  the  concentric  i-ings  are  less 
prominent,  and  the  valves  more  inflated  and  less  distinctly  triangular.  Another 
similar  form  is  P.  Malhosi,  Pictet."     See  also  P.  cordata  (below). 

The  specimens  from  the  Cambridge  Greensand  were  regarded  by  Seeley  as 
constituting  a  variety  (P.  derussata  var.  triamjularis),  but,  as  was  pointed  out  by 
Jukes-Browne,  they  agree  in  all  essential  characters  with  P.  decussatu,  differing 
only  in  their  smaller  size.  Specimens  of  V.  decussata  found  in  the  Gault  of 
Folkestone  are  larger  than  those  found  in  the  Cambridge  Greensand,  I)ut  not  so 
large  as  the  examples  in  the  Chalk. 

Beviarks. — In  England  this  species  has  not  been  found  above  the  Cenomanian 
(zone  of  H.  svh(jloI)osus),  but  on  the  Continent  it  appears  to  range  up  into  the 
Senonian.  In  many  of  the  English  specimens  the  original  shape  has  been  modified 
l)y  crushing,  and  that  also  ajDpears  to  be  the  case  with  some  of  the  examples 
figured  by  foreign  authors. 

Tj/pe. — The  type  from  the  Lower  Chalk  near  Brighton,  and  the  specimen 
figured  by  Sowerby  from  the  Chalk  Marl  of  Hamsey,  and  the  one  figured  by 
Dixon,  cannot  now-  be  found. 

Distriltutio)!. — Gault  of  Folkestone.  Cambridge  Greensand.  Chalk  .Marl  of 
Ventnor,  Culver  Cliff,  Eastbourne,  Hamsey,  Middleham,  Offham,  Glynde  and 
Folkestone.  Totternhoe  Stone  (zone  of  Bulastcr  sitbylulosux)  of  Arlesey  and 
Burwell. 

1  'Moll.  Foss.  Grts  verts  de  Gemve '  (1862),  p.  405,  pi.  xxix,  fig.  2.  Moesdi,  '  Mon.  Pliola- 
douijeu'  (1875),  p.  97,  pi.  xxxii,  figs.  2-4 

-  '  Melanges  Pak'ont.'  (1868),  p.  92,  pi.  xix,  fig.  3.    Moefecli,  op.  c-it.,  p.  88,  pi.  xxx,  fig.  5,  pi.  xxxv,  fig.  1. 


MY0PH0LA8.  253 


Pholadomya  corpata,  Tat<',  18G5.     Plate  XLII,  fig.  2  <i — r. 

1865.     PHOLADOMy.\  coEDATA,  if.  Tctte.     Quart.  Jmirn.  Geol.  Soc,  vol.  xxi,  p.  4(), 

}il.  iv,  fii^.  1. 

BeniarliS. — A  specimen  fouml  in  the  I'pper  Chalk  (zone  of  Jielemnitella  mncro- 
■nata),  now  in  the  Norwich  Museum  (No.  3339),  is  probal)ly  an  example  of  P. 
cordata,  Ijut  unfortunately  the  anterior  part  of  the  shell  is  imperfect.  In  this 
species  tlie  anterior  curvatni-e  of  the  umbones  is  greater  and  the  de2)ression  in 
front  of  them  deeper  than  in  P.  decu.ssata ;  also  the  anterior  flattened  part  is 
relatively  smaller,  since  the  greatest  diameter  of  the  shell  occurs  at  about  one  third 
of  the  lengtli  from  the  anterior  end.  The  ty})es  of  P.  cardata  from  the  Upper 
Chalk  of  Ireland  are  in  the  Museum  of  Practical  Geology  (Nos.  23,(328 ;  28,629). 


Genus — Myopholas,  H.  BourilU,  1007. 

('  Bull.  Soc.  gcol.  de  France,'  ser.  4,  vol.  vii.  p.  Iu7.) 

Myopholas,  sp.  cf.  SEMicosTATA  {Aijunsi::),  184-2.     Plate  XLIT,  fig.  3//,/;. 

Descriptiun. — Shell  oval,  short,  con.siderably  ine([uilateral,  anterior  part  convex, 
230Sterior  part  compressed;  anterior  and  posterior  margins  rounded.  Umbones 
curved  inwards  and  forwards.  Eather  more  than  half  of  tlie  shell — the  anterioi^ 
part — is  ornamented  with  thirteen  narrow,  sharp,  radial  ribs,  which  are  separated 
by  broad,  flat,  or  slightly  concave  interspaces ;  posterioi-h*  these  ribs  become 
smaller  and  less  widely  separated ;  on  the  middle  part  of  the  shell  a  few  indistinct 
concentric  ribs  are  seen.  The  posterior  part  of  the  shell  is  nearly  smooth,  and  is 
separated  from  tlie  ribbed  area  l)y  a  slight  depression  ;  a  cui'ved  carina  extends 
from  the  posterior  side  of  tlie  iiml)i)  towards  the  postero-vciilral  extremity. 

Affinities. — Only  one  specimen  lias  Ijeen  seen;  it  resend)les  closely  M.  seiui- 
costata  (Agassiz^),  but  is  rather  shorter,  and  the  posterior  limit  of  the  ribbed  area 
is  more  sharply  defined  than  in  most  examples  of  M.  yciiiicoslnfa.     Judging  from 

1  'Etudes  crit.  Moll.  Foss.,'  Mves  (1842),  p.  51,  pi.  ii,  figs.  1,  2,  pi.  iii',  fig.  11.  Pictet  ami 
Campiche,  'Foss.  Terr.  Crct.  Ste.  Croix'  ('  Mati'r.  Pal.  Suisse,'  ser.  4,  1865),  p.  77.  pi.  cv,  figs.  1,  2. 
Moescli,  'Mod.  Phohulomveu  '  (1874),  p.  85,  pi.  xxx,  fig.  4,  i)l.  xxxiii,  figs.  3,  4.  pi.  xxxvi,  fig.  1. 
Douvillr,  ■  Bull.  Soc.  geol.  de  France,'  ser.  4,  vol.  vii  (1907),  p.  112,  pi.  ii,  fig.  8.  Jloescli  includes  as 
a  svnonvm  PhoJadomya  Trihohti,  Pictet  ami  Caiiipiclie,  op.  cit.,  p.  8!l,  \>\.  cvi,  fig.  8.  Pictet  and 
CanipicLe  include  P.  Moreuna,  Buviguier,  '  Statist,  gi'ol.,  etc.,  de  la  Meuse  '  (1852).  Atlas,  p.  8.  pi.  viii, 
figs.  21.  22. 


254  CRETACEOUS   LAMELLIBRANCHIA. 

the  figures  given  by  several  authors,  that  species  varies  considerably,  so  that  it 
seems  probable  that  when  more  English  specimens  have  been  obtained  it  will  be 
possible  to  refer  them  definitely  to  M.  semicostata. 

Distribution. — Lower  Greensand  of  Furze  Hill,  Faringdon. 


Genus — Gon'iomya,  L.  Ar/assi;:,  1842. 
('  Ktudes  t-rit.  Moll.  Foss.,"  Mves,  pp.  xii,  1.) 

GoNioMYA  Archiaci  {Pictct  and  Eenevlrr),  1855.     Plate  XLII,  figs.  4,  5. 

1855-6.  Thracia  Archiaci,   F.  J.   Pidet    and   E.    Beneiner.     Foss.   Terr.    Aptieii 

(Matt'r.  Pa,l.  Suisse,  ser.  1),  p.  67, 
pi.  vii,  fii,'.  5. 
1858.  -  —  Pidet  and  Renevier.     Ibid.,  p.  176. 

1865.     Pholadomya  thracioides,  F.  J.  Pidet  and  G.  Campidie.     Terr.  Crut.  Ste. 

Croix  (Mater.  Pal.  Suisse,  ser. 
4),  p.  92  (Gohiomi/a). 
1870.     GoNioMYA  Archiaci,  F.  Stoliczka.     Palseout.  Iiidica,  Cret.  Fauua  S.  liidia, 

vol.  iii,  p.  75. 

Description. — Shell  ol^long,  convex,  nearl}^  equilateral.  Anterior  margin 
rounded.  Ventral  margin  slightly  convex  or  nearly  straight,  ncai'ly  parallel  with 
the  dorsal  margin.  Posterior  margin  truncated,  oblique,  slightly  convex,  forming 
a  rounded  angle  with  the  ventral  margin  and  an  obtuse  angle  with  the  postero- 
dorsal  margin.  Umbones  of  moderate  size,  with  a  faint  rounded  carina  extending 
postero-ventrally,  above  which  the  shell  is  compressed ;  lunule  and  escutcheon 
elongate,  depressed,  limited  by  carina?. 

Ornamentation  :  Anteriorly  to  the  umbones  there  is  a  ribbed  area  in  which  the 

ribs  extend  oblicjuely  backwards ;  posteriori}'  to  the  umbones  is  another  ribbed  area 

in    which    the  ribs   are  nearly  perpendicular  to  the   postero-dorsal  margin,   Ijut 

slightly  curved  ventrally.     The  anterior,  ventral,  and  postero-dorsal  parts  of  the 

shell  are  Avithout  ribs,  and  show  growth-lines  only.     Near  the  umbo  the  ril)s  of 

the  two  areas  are  connected  by  horizontal  ribs,  but  ventrally  these  horizontal  ril)s 

are  absent  or  indistinct.     Some   parts  of  the  shell  are  marked  by  rows  of  small 

pits. 

Measurements  : 

(1)  (2)  (3) 

Length  .  .         33         .         28         .  19  mm. 

Height  .  .         19         .         IG         .         11     „ 


'& 


(1 — 3)  Crackers,  Atherfield. 


GONIOMYA.  255 

Affinities.- — This  species  is  less  inequilateral,  and  the  ri])s  are  less  extensively 
developed  than  in  (J.  candata,  Agassiz.^ 

Bemarks. — English  examples  of  this  species  were  identified  by  Pictet  and 
Renevier,  who  state  that  the  forms  referred  by  Forbes-  to  Pholaclomya  Agassizi 
are  really  specimens  of  G.  Atrhiari. 

Type.— From  the  Aptian  of  the  Perte-du-Rhone. 

DistrihuiicDi. — Lower  Greensand  (Crackers)  of  Atherfield.^ 

GoNiOMYA  Mailleana  {d'Orhi,ju)j),  18-1-5.     Plate  XLII,  figs.  6,  7. 

1845.     Pholadomta  Mailleana,  A.  (TOrhiyny.     Pal.  Frauc.  Terr.  Cri't.,  vol.  iii, 

p.  355,  pi.  ceclxiv,  figs.  1,  2. 
1845.     GoNioMYA  Mailleana,  L.  Agassiz.     Etudes,  crit.  Moll.  Foss.,  Myes,  p.  xiv. 
1850.     Pholadomia  Mailleana,  A.  d'Orhigny.     Prodr.  de  Pal.,  vol.  ii,  p.  157. 
1854.     Pholadomta  Mailleana,  /.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  220. 
1865.  —  —F.J.  Pictet  and  G.  Campiche.     Terr.  Crct.  Ste. 

Ci'oix  (Mater.  Pal.  Suisse,  ser. 
4),  p.  93  (Goniomya). 
?  1868.     Pholadomya  Mailleana,  A.  Briart  and  F.  L.  Cornet.     Meule  de  Bracque- 

giiies  (Mt'm.  cour.  et  Mem.  des 
Sav.  ctraugers,  vol.  xxxiv),  p.  83, 
pi.  vi,  fig.  12. 
1870.     Goniomya  Mailleana,  F.  Stoliczka.      Palieont.    ludiea,    Cret.   Fauua  S. 

India,  vol.  iii,  p.  75. 
?  1885.     Pholadomya  (Goniomya)  Mailleana,  F.  NiitUng.     Die  Fauna  d.  baltisch. 

Cenomau.  (Palteout.  Abbandl., 
vol.  ii),  p.  36,  pi.  vi,  fig.  9. 

Descripiiuii. — Shell  elongate,  sub(iuadrate,  convex,  very  ine(juilateral.  Anterior 
part  not  so  high  as  the  posterior  part,  compressed,  with  rounded  margin. 
Antero-dorsal  margin  concave.  Postcro-dorsal  margin  long,  nearly  straiglit,  and 
nearly  parallel  to  the  slightly  convex  ventral  margin.  Posterior  margin  truncated, 
oblique,  forming  a  rounded  angle  with  the  ventral  margin,  and  an  obtuse  angle 
with  the  postero-dorsal  margin.  Umbones  pointed,  directed  anteriorly.  Lunide 
concave,  elongate-ovate,  limited  by  a  carina.  Escutcheon  long,  deep  near  the 
umbones,  limited  by  a  carina.  Between  the  carina  of  the  escutcheon  and  a 
rounded  ridge  extending  from  the  umbo  towards  the  postero-ventral  margin  the 
shell  is  concave. 

1  'Etudes  crit.  Moll.  Foss.,'  Myes  (1842),  p.  22,  pi.  ih,  figs.  1—3,  pi.  i,  fig.  1.  Plwlndomya 
Agassizi,  d'Orbigny,  'Pal.  Franc.  Terr.  Cret.,'  vol.  iii,  p.  352,  pi.  ccclxiii,  figs.  1,  2;  Pictet  and 
C'ampielie,  '  Foss.  Terr.  Cret.  Ste.  Croix '  ('Mater.  Pal.  Suisse,'  ser.  4,  1865),  p.  84,  pi.  cvi,  figs.  4 — 6. 

2  '  Quart.  Jouru.  Geol.  See.,'  vol.  i  (1845),  p.  239.     Morris,  '  Cat.  Brit.  Foss.,'  ed.  2  (1854),  p.  176. 
■'  An  imperfect  specimen  of  Goniomya  from  the  Tealby  Limestone  of  Claxby  is  iu  the  Sedgwick 

Museum,  Cambridge. 


256  CRETACEOUS    LAMELLIBRAXCHIA. 

Ornamentation  consists  of  rounded  riljs ;  those  in  front  of  tlic  niabones  are 
nearly  straight  and  slope  obliquely  backwards  and  downwards  ;  those  behind  the 
umbones  are  curved  and  more  or  less  nearly  parallel  to  the  posterior  and  postero- 
dorsal  margins;  near  the  ventral  margin  the  ribs  become  more  nearly  concentric 
and  are  often  less  distinct  (especially  on  the  median  part)  than  on  tiie  dorsal 
{lortion  of  the  shell. 

AQinitiea. — This  species  differs  from  (j.  ih'.-^iijnuta  (Goldfuss)'  in  the  smaller 
curvature  of  the  ventral  margin,  and  in  the  truncated  form  of  the  posterior 
margin.  It  is  closely  allied  to  (I .  ciiusiijuiitu,  Romer,-  but  the  anterior  curvature 
of  the  umbones  is  more  marked. 

Remarks. — This  species  has  been  identified  b}'  comparison  with  a  specimen 
given  me  by  M.  Raoul  Fortin  from  the  same  locality  as  the  type. 

Ttjpe. — From  the  Cenomanian  of  Mte.  Ste.  Catherine,  Rouen. 

Disfrihnfion. — Upper  Greensand  (zone  of  Bfltlifnhachia  roatrnta)  of  Blackdown, 
Devizes,  and  near  Maiden  Braillev.      Base  of  Chalk  Marl  of  Chard. ^ 


i^(u;i/Z//— PLEUROMYID.^,  Z///e/. 

Genus — P;.EDR0MTA,  L.  Aijassiz,  1842. 
('  Etudes  crit.  Moll.  Foss.,'  Myes,  p.  231.) 


Pleuromya  Orbignian.v  (Uoiiilliev),  1847.     Plate  XliTTI,  figs.  1,  2  a — c. 

1847.     PanoPjEa.  Obbigniana,  C.  Rouillier.     Bull.  Soc.  Imp.  Nat.  Moscou,  vol.  xx, 

p.  407;    vol.    xxi    (184.8),    p.   281, 
pi.  G,  fig.  24. 

JJescrijjf.ion. — Shell  oval,  convex,  inequilateral,  with  a  small  posterior  gape. 
Anterior  and  posterior  margins  rounded.  Ventral  margin  considerably  convex. 
Umbones  moderately  prominent,  incurved.  Shell  depressed  in  front  of  and  l)ehind 
the  umbones.  Surface  nearly  smooth,  but  ornamented  with  linear,  radial  ribs, 
which  are  sometimes  parallel,  sometimes  irregular;  in  some  places  the  ribs  are 
replaced  by  rows  of  minute  tubercles. 

Affinities. — The  English  specimens  agree  closely  with  examples  from  the  Lower 

1  '  Petref.  Genu.,'  vol.  ii  (1840),  p.  264,  pi.  cliv,  fig.  13.  Holzapfel,  '  Mollusk.  Aachen.  Kreide ' 
(Palseoutographica,  vol.  xxxv,  1889),  p.  153. 

■  'Die  Versteiu.  d.  nord-deutsfli.  Kreidegeb.'  (1841),  p.  75,  pi.  x,  fig.  3.  Midler,  'Mollusk. 
Untersen.  v.  Braunschweig  u.  Ilsede'  (1898),  p.  71,  pi.  x,  fig.  7. 

^  A  small  spcL'iniou  of  Goniunn/a  has  beeu  found  in  the  Chalk  of  Triiuiugham  by  Mr.  R.  M. 
Brydone. 


TJOPTRTHA.  257 

Volgian  of  Moscow,  wliich  were  identified  by  Prof.  Pavlow,  l)ut  their  resemblance 
to  Rouillier's  fio-m-e  is  not  quite  so  close.  Some  of  the  smaller  specimens  approach 
P.  peregriaa  (d'Orbigny'),  which  is  said  to  differ  from  /'.  Orbujmana  by  smaller 
curvature  of  the  ventral  margin,  the  presence  of  a  shallow  depression  extending  to 
the  ventral  margin  below  the  umbones,  and  l)y  the  ornamentation  consisting  of 
radial  rows  of  minute  tubercles  instead  of  linear  ribs.  One  specimen  from  Spilsby, 
however,  shows  both  types  of  ornamentation,  suggesting  that  the  two  species  are 
not  really  distinct.  The  hinge  is  not  seen  in  any  of  the  English  specimens  of  /'. 
Orhirjniaiia,  but  the  figure  given  liy  Rouillier,  although  not  fpiite  satisfactory,  is 
suggestive  of  I'miopea;  the  form  of  the  shell,  however,  resembles  that  of  some 
Jurassic  species  of  Flenromiin. 

DistrilmtloiL. — Spilsby  Sandstone  (zone  of  Belemuitus  laturalls)  of  Dounington. 


Famil I/— FOnOMYAGIDM,  Dall. 
Qeniis — LiorisTHA,  F.  B.  Meel;  1864. 

('  Check  List  Invert.  Foss.  N.  America,'  pp.  12,  32  ;  T.  A.  Conrad  in  Kerr's  '  Keport  Geol.  Survey 
N.  Carolina,'  vol.  i,  187.5,  Appendix  A,  p.  28  ;  Meek, '  Invert.  Cret.  and  Tert.  Foss.  U.  Missouri,' 
1876,  p.  227.) 

Section — PsiLOMYA,  Meek,  187G. 
(Ibid.,  p.  229.) 


LiopiSTU.v  (PsiLo.MY.\)  g[G.\ntd:.v  [Son-erhij),  1818.      Plate  XLIII,  figs.  ;5,  4;    Plate 

XLIV,  figs.  1,  2. 

1811.     CoRBULA  ?,  /.  Parkinson.     Or;:,'anic  Eemaius,  vol.  iii,  p.  226. 

1818.  —         GiGANTEA,  J.   Sowerby.     Miu.  Couch.,   vol.   iii,   p.    lo,   pi.    ccix, 

figs.  5—7. 
1850.     Pholadomya  —         A.  d'Orhiijnij.     Prodr.  de  Pal.,  vol.  ii,  p.  157. 
1854.     Thetis  —         J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  227. 

18(3.5.         _      ?  _         F.  J.  Pidet  and  G.  Campiclie.     Ten-.  Crct.  Ste.  Croix 

(Matc'r.  Pal.  Suisse,  ser.  4),  pp.  199,  210. 
1870.     POROMTA  ^       —         F.  StoUczka.     Palseout.  Indica,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  42. 
1882.     LiOPiSTHA        —         P.  de  Loriol.     Gault  de  Cosne,  p.  45,  pi.  vi,  figs.  1—5. 

1  Murchison,  Verneuil,  and  Keyserling,  'Geol.  de  la  Russie  de  I'Europe,'  vol.  ii  (1845),  p.  468, 
pi.  xl,  figs.  10—12.  The  hinge  is  figured  by  Zittel,  '  Handbuch  d.  Paliiont.,'  vol.  ii,  p.  125.  fig.  179, 
and  '  Gruudziige  d.  Paliiont.,'  ed.  2  (1903),  p.  330,  fig.  732. 

34 


258  CRETACEOUS   LAMELLIBRAKCHIA. 

Description. — Shell  large,  rather  thick,  oval,  elongate,  inflated,  the  posterior 
2iart  compressed,  very  inequilateral.  Anterior  part  very  short,  with  rounded 
margin,  but  its  dorsal  part  only  slightly  curved.  Ventral  margin  forming  a 
considerable  curve.  Posterior  margin  obliquely  truncated,  more  or  less  rounded. 
Postero-dorsal  margin  nearly  straight.  Umbones  large,  prominent,  pointed, 
iuroUed,  and  with  a  more  or  less  considerable  forward  curvature.  A  rounded 
carina  extends  from  the  front  of  the  umbones  to  the  middle  of  the  anterior  margin 
and  foi-ms  the  boundary'  of  a  deeply  excavated  area  in  front  of  the  umbones. 

Ornamentation  consists  of  liroad,  rounded,  concentric  ril)s  on  the  dorsal  part 
of  the  valves  except  on  the  anterior  excavated  area.  In  passing  vcntrally  these 
ribs  become  less  prominent  and  are  soon  represented  by  concentric  lines.  Rather 
widely  separated  radial  rows  of  minute  tubercles  are  present  and  leave  small  pits 
when  broken  off.     Near  the  umbo  small  radial  ribs  are  present. 

Meastirements  : 

(11  (2)  (;i) 

Length        .  .  128         .         110         .         90  mm. 

Height        .  .  89         .  82         .         08     „ 

(1—3)  Blackdown. 

Affinities. — This  species  resembles  L.  {Psilomya)  .^iq-)erha  (Stoliczka^),  but 
differs  in  outline,  in  the  concentric  ribs  being  confined  to  the  dorsal  part  of  the 
shell,  and  in  the  less  inflated  form  of  the  valves. 

liemarks. — In  the  small  examples  of  this  species  the  shell  is  relatively  shorter 
and  more  nearly  orbicular  in  outline  and  the  concentric  ribs  cover  the  whole 
or  nearly  the  Avhole  of  the  valves.  The  radial  ribs  near  the  umbo  are  seen 
in  only  a  few  specimens. 

Ttjpe. — From  Blackdown,  in  the  British  Museum. 

Distrihntioii. — Upper  Greensand  (zone  of  Srlila'ulxicliid  rustrata)  of  Blackdown. 

LioPiSTiiA,  sp.      Plate  XLIII,  fig.  5*^' — r. 

Description. — Shell  oval,  slightly  inequilateral,  inflated,  posterior  part  com- 
pressed, with  a  shallow  furrow  near  the  postero-dorsal  margin,  concave  in  front 
of  the  umbones.  Anterior  and  posterior  uuxrgins  rounded;  ventral  margin 
considerably  convex.     Umbones    prominent,  curved    inwards  and  forwards. 

Ornamentation  consists  of  numerous  (about  twenty-nine),  narrow  radial  ribs 
l)eai'ing  small  tubercles,  and  separated  l)y  concave  interspaces  of  greater  breath 
than  the  ribs.  On  the  postero-dorsal  part  of  the  shell  ribs  are  absent.  The 
ribs  are  crossed  by  faintly  marked  concentric  rings. 

Reinarldi. — The  only  exanq)le  of  this  species  which  has  been  seen  does  not 
1  '  PalseoTit.  Indica,  Cret.  Fauna  S.  India  '  (1870),  p.  4.S,  pi.  iii,  figs.  2 — 4. 


CUSPID  ARIA.  259 

show  the  hinge,  but  it  is  provisiouully  referred  to  LiopistJia  on  account  of  its 
external  resemblance  to  some  species  of  that  genus. ^  It  should  lie  noted,  how- 
ever, that  it  is  also  similar  to  some  species  which  are  believed  to  belong  to  the 
genus  PJioladomi/a." 

Bisty'ihuflo)!. — Red  Limestone  of  Hunstanton. 


i^'rt)«/Z//— CUSPID ARIID.E,  DalL 

Genus — CaspiDAiMA,  G.  D.  Nardo,  1840. 
('  Anu.  Sci.  Lombardo-Veueto,'  vol.  x,  p.  49.) 


CuspiDAKiA  SAiiAUDiANA    (Firfcf   find  Camjnclie),  186-i.      Plate  XLIII,   fig.  6o,h; 

Plate  XLIV,  fig.  Sn,l. 

1864.     NE^ffiiEA  Sabaudiana,  F.  J.  Pidet  and  G.  Campiche.     Foss.  Terr.  Cret.  Ste. 

Croix  (Mater.  Pal.  Suisse,  ser.  4), 
p.  40,  pi.  e,  figs.  5 — 7. 

Descnptioii. — Shell  inflated,  oval,  oblique,  slightly  inequivalve,  anterior  part 
sloping  rapidly  to  the  uiargin,  posterior  ])art  compressed  and  produced  into  a 
pointed  beak.  Anterior  margin  rounded ;  ventral  margin  convex,  curving  upwardsi, 
and  passing  gradually  into  the  posterior  margin.  Umbones  curved  inwards  and 
slightly  backwards.  A  narrow  postero-dorsal  area  is  bent  at  an  angle  Avith  the 
sides  of  the  shell,  and  is  limited  by  a  carina. 

Ornamentation  consists  of  strong,  concentric  ribs,  most  of  which  are  con- 
tinued on  to  the  posterior  beak,  where  they  become  rather  smaller  and  closer 
together ;  on  the  sides  of  the  ribs  and  in  the  furrows  are  ii  few  faint  concentric 
lines.     Length  14  mm.;  height  H  mm. 

AMiiifies. — This  species  is  more  inflated,  the  anterior  part  is  more  rounded, 
and  the  concentric  riljs  are  stronger  than  in  C.  jiitlchra  (Sowerby). 

T]ipe. — From  the  Gault  of  the  Perte-du-Rhone. 

Distnbntion. — Lower  Gault  of  Folkestone. 

1  See,  for  example,  Stoliczka,  '  Crot.  Fauna  S.  India,'  vol.  iii  (1870),  pi.  ii,  figs.  10,  11  ;  Moesch, 
' Men.  Pholadomyen '  (1874),  pi.  xxxv,  fig.  5;  Geinitz,  'Das  Elbthalgeb.  iu  Sachseu '  (' Palaeonto- 
gi-aphica,' vol.  XX,  pt.  2,  1873),  pi.  xix,  figs.  6,7;  Wcller.  'Crct.  Pal.  New  Jersey,'  vol.  iv  (1907). 
pi.  Iviii,  figs.  3 — 9. 

-  E.g.  P.  suhdmengig  (d'Orbigny),  'Pal.  Franc.  Terr.  Cret.,'  vol.  iii  (1844),  p.  38,  jd.  eel,  figs. 
1—3,  and  '  Prodr.  de  Pal.,'  vol.  ii  (1850),  p.  1-57. 


2G0  CRETACEOUS   LAMELLTBRANCHTA. 


Cuspin.vKiA  u.\DU[,ATA  {Sowerhi/),  1827.     Plate  XLIV,  fig.  4. 

1827.     NucuLA  UNDULATA,  J.  df  C.  Soivefhi/.     Min.  Couch.,  vol.  vi,  p.  104,  jil.  dliv, 

fig-  3. 
1854.     Ne^ra  ?        —  J.  Morris.     Cat.  Brit.  Foss.,  eil.  2,  p.  216. 

1866.         —  —F.J.  Picfef  and  G.  Campiche.     Foss.   Terr.  Cret.   Ste. 

Croix  (Mater.  Pal.  Suisse,  ser.  4),  p.  421. 
1871.         —  —  F.  StoUckza.     Palaeont.  Indica,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  322. 

Eemarlis. — A  few  .specimens  resembling  Sowerby's  figure  of  G.  utidulatd  Lave 
been  found.  They  appear  to  differ  from  G.  SabaucUana  only  in  tlie  less  oblique 
form  of  the  shell  and  the  more  convex  postero-ventral  margin.  More  specimens 
are  needed  in  order  to  determine  whether  G.  SaJiandidna  and  G.  iimJulata  are  reall}' 
distinct  or  only  varieties  of  one  species. 

Tijpe. — The  type  was  preserved  in  pyrites,  and  came  from  Folkestone ;  it  was 
formerly  in  the  British  Museum,  but  has  now  perished. 

Distrihution. —  Gault  of  Folkestone. 


CusPiDAEiA  PULCHKA  (Sowi'rhi/),  1850.     Plate  XLIV,  figs.  .5,  6. 

1850.     Leda  pulchra,  J.  de  C.  Soirerbij  in  F.  Bixon.     Geol.  Sussex,  p.  346  (p.  382, 

ed.  2),  pi.  xxviii,  fig.  10. 
1864.       —     ?       —        J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  205. 
1897.     CuspiDARiA  CAUDATA,  H.  Woods.     Quavt.  Journ.  Geol.  Soc,  vol.  liii,  p.  393, 

pi.  xxviii,  figs.  19,  20. 

Description. — Shell  convex,  with  the  posterior  and  antero-dorsal  parts  com- 
pressed ;  sub-triangular,  oblique,  somewhat  inequilateral,  highest  in  front  of  the 
umbones.  Dorsal  margin  nearly  straight.  Anterior  margin  slightly  convex. 
Antero-ventral  margin  rounded.  Ventral  margin  curving  upwards  and  passing 
gradually  into  the  posterior  margin,  which  forms  an  acute  angle  with  the  postero- 
dorsal  margin.  Umbones  pointed,  curved  inwards  and  slightly  backwards. 
Ornamentation  consists  of  regular,  concentric  ribs  which  become  indistinct  on  the 
antero-dorsal  and  postero-dorsal  parts. 

Measurements  ; 

(1)  (2) 

mm. 


(1) 

(2) 

Length 

. 

27 

22 

Height 

. 

19 

15 

Thickness 

. 

14 

11 

(1,2)   Upper  Chalk, 

Norwicli. 

palcxontoovapbical  Socict\?,   lOlO. 


A     J\r  O  N  O  G  R  A  P  H 


OF    THE 


CRETACEOUS    LAMELLIBIUNCHIA 


ENGLAND 


BY 


HENRY  WOODS,  M.A. 

UNIVERSITY    LKCTUUKU    IN    TALiKOZOOLOli Y,    CAMURIUGE. 


VOL.  IL     PART  VIL 

ixocERA:\rus. 

Pages  261—284;   Plates  XLV— L. 


LOX  DON  : 
PRINTED     Foi;     T]IE     PA  L.KUNTOG  K  A  1' H  I  C  A  L     SOCIETY. 

Jaxi'auy,  ion. 


PBINTEU  BY  ADLABD  AND  SON,  LONDON  AND  DORKING. 


CUSPIDARIA.  261 

Affinities. — When  describing-  tlie  Mollusca  of  the  Chalk  Rock  in  1897  only  an 
imperfect  specimen  of  G.  pidciiva  was  available  for  study,  and  1  identified  it  with 
G.  camiata  (Nilsson).  Two  better  specimens  from  Norwich  have  now  been  seen, 
and  anew  figure  of  Nilsson's  type  has  been  published  I)y  Hennig.'  The  English 
form^figured  by  Sowerby  as  I^i'da  pulrJira — differs  from  the  type  of  ('.  cnndnta  in  the 
relatively  greater  height  of  the  anterior  ])ar( of  the  shell,  the  more  nearly  posterior 
position  of  the  umbones,  and  in  the  posterior  rostrum  proceeding  from  the  \o\d\ 
of  the  hinge-line  instead  of  below  it.  < '.  piilrlim  approaches  closely  the  specimen 
figured  by  Goldfuss"  as  G.  caiuhitu,  and  it  was  chiefly  on  account  of  this  resem- 
blance that  I  identified  the  English  form  with  Nilsson's  species.  Stoliczka^  and 
Hennig,  however,  consider  that  Goklfuss'  specimen  is  nut  an  example  of  ('.  cauddta. 
If  all  the  specimens  figured  by  foreign  writers  as  G.  (-midala  really  belong  to  that 
species  then  it  is  obviously  extremely  variable  and  might  well  include  G.  jndchra. 
Without  an  oppoi'tunity  of  studying  a  series  of  foreign  specimens  and  a  larger 
number  of  English  examples  it  seems,  at  present,  preferable  to  regard  G.  puirJira 
as  distinct  from  G.  candata.  None  of  the  English  specimens  shows  e^'idence  of  the 
existence  of  such  a  long  posterior  beak  as  is  present  in  the  type  of  G.  Cdudafa. 

A  specimen  of  Gii.^^iidaria  from  the  Upper  Greensand  of  Uevizes  (Plate  XLIV, 
fig.  7)  resembles  some  specimens  of  G.  judrlini  and  may  be  provisionally  referred 
to  that  species. 

Ti/2>e. — The  type,  from  the  '•  Chalk  of  Kent,"  cannot  noAV  be  found. 

Dint ribul ion. — Chalk  Rock  of  Cuckhamsley,  Berkshire,  and  Henley  Park. 
Up|)er  Chalk  (zone  of  L'dcniiiilclla  niucru)iafa)  of  St.  Giles'  Gate  and  Horstead, 
near  Norwich. 


1  'Kevis.  Lamellibr.  i  Nilssou's  Petrific.  Suecana  Format.  Cret.'  (1807),  p.  62.  pi.  iii,  fig.  28; 
EavE.  '  Molliisk.  i  Daumarks  Kridtafi.  I.  Lamellil.r.'  (1902),  p.  (35  [133],  pi.  iv,  fi-.  2t. 

-  '  Petref.  Germ.,'  vol,  ii  (1840),  p.  251,  pi.  cli,  fij,'.  17.  Compare  also  WoUymauu,  •  Seuoiis  v. 
Bieweude'  ('Jalirb.  d.  k,  preuss.  geol.  Landesaust.,'  fiir  1900),  p.  23,  fig.  5 ;  Miiller,  '  Mollusk.  d. 
Uutersen.  v.  Braunscliweig  u.  lUcdc  '  (1898),  p.  77,  pi.  x,  lii,'s.  10, 11  ;  Wolleiiumii.  •  Fauna  dvr  Liiue- 
Imrg.  Kreide'  (1902).  p.  80. 

^  '  Palaiout.  Iiidica,  Cret.  Fauna  S.  India,"  vol.  iii  (1870),  p.  41. 


35 


2(32  CRETACEOUS    LA.M  KLIJIJUAXCll  I  A. 

i'W7»////-l'EllNIi).E,  Zlnd. 

(Coiithiiied  frniii  pngf  05.) 


(li'lillS — IxoCKItAMI'S,    J.    Snirrrlii/,^    ISIO. 

(J.  Piirkiasou  [ex  Sowerbj  MS. J,  'Traus.  Gruol.  Sac.,'  sor.  1,  vol.  v,  1819,  p.  55.    J.  Sowurby, 
'Traus.  Liuu.  Soc.,'  vol.  xiii,  1822,  p.  455.) 


Inocebamiis  NHoOD.MiK.Nfsis,  iV Orhhjii ij ,  1 8 iij.     Pliite  XIjV,  fig.s.  1,  2. 

18-10.     iNociiR.VMus  NEoco.MiENSis,  A.  d' Orbi'jiii/.     Pal.  Fram;.  Torr.  Ci\''t.,  vol.  ili, 

p.  50;3,  pi.  cccciii,  figs.  1,  2. 
1850.  —  —  ,rOrl,:,i,n/.     Vi-odr.  de  Pal.,  vol.  ii,  p.  83. 

1854.  —  —  J.  Morris.     C.it.  Brit.  Foss.,  eil.  2,  p.  170. 

1855.  —  —  G.  Collect II.     Moll.  Fos-i.  de  ITouue,  p.  107. 
1869.               —                       —           F.J.FidetaiulG.aunpiche.    Foss.  Terr.  C ret. 

Ste.  Croix  (Mat.'r.  Pal. 

Suisse,  ser.  5),  p.  104. 

1900.  —  —  A.    Wollem-.mn.      Die   Bivalv.    u.    Gastrop.    d. 

deutscli.      u.      holljiud. 
Neocoms,  p.  (50. 
?  1905.  —  E.    llu-hurt.      Die   Fauna    d.    SL-liauniliui-ix- 

Lippe'scheu      Kreidemulde, 
p.  44,  pi.  ix,  fiLjs.  4-6. 

Descrij.itluii. — Shell  iueciuivalve,  vei-y  iiit'quiliiteral,  a  little  liiu'lier  than  long. 
Valves  convex,  with  flattened  sides,  and  the  postevior  part  uoiupre.'^.sed.  Anterioi' 
margin  iicnrly  straiglit  ;  posterior  and  ventral  margins  rounded.  Posterior 
margin  Cdi'iiiing  nii  obtuse  angle  with  the  hinge-line.  Anterior  part  nearly 
peri)enilicul;n'  to  the  plane  of  the  valves  and  excavateil  near  tlie  nndjones. 
Und)ones  terminal,  eurved  inwards  and  Forwards.  Uinge-line  eipial  to  mure  tlian 
Indf  the  height  of  tlie  sliell,  and  nia]<ing  an  angle  of  ahoiit  l(H»'  willi  the  anterior 
margin. 

Ornam'ntation  con.sists  of  narrow,  regular,  coneenti'ie  rilis  witli  an  lui.sym- 
metrical  eiirvature;   the  interspaces  are  I)road  and  regularly  concave. 

'  In  roarran^'injj  llic  lullcrtiou  of  Iimeenuiii  in  tiir  IJrilisli  Muscuni,  Mr.  K.  B.  Newton  and  Mr. 
C.  D.  Sherboru  have  found  several  tvpe-speeinieus,  (he  existence  of  which  liiid  not  been  prcviuuslv 
reeo<rnised;  this  discovery  has  great Ij  facilitated  my  work.  I  am  also  imlel)ted  to  Mr.  Newt(Ui  and 
Mr.  Sherborn  for  assistance  in  selectiny  specimens  for  fi^'uring.  I  wish  to  thanl;  Jlr.  0.  1'.  Chat  win 
for  infoniiatiiin  respecting  1  lie  zonal  distribution  of  the  sjioeies  of  Iiinrerniiiii.-<  in  (he  Chalk  and  for 
other  assistance  Dr.  Blackniore,  Dr.  Rowe,  and  Mr.  G.  E.  Dildey  have  helped  by  the  loan  of 
numerous  specimens  from  their  collections. 


INOCERAMUS.  203 

Affinities. — Sec  I.  (nif/liciis  (p.  201). 

/.  iieocomtensis  appears  to  be  allied  to  ./.  Kivuhli,  Scliliiter,'  of  wliicli  only  one 
figure  has  yet  been  published.  'I'li(>  differences  seen  are  in  the  greater  relative 
height,  the  more  inequilateral  form,  and  the  greater  convexity  of  the  curve  of  the 
ribs  of  1.  ncocomiensis.^ 

Iieiii(ni'f<. —  This  species  was  first  recorded  in  England  by  Fifton.  Onlv  a  few 
specimens  have  been  seen;  they  agree  fairly  well  with  d'Orbigny's  figure,  but  the 
ribs  appear  to  be  better  defined,  and  usually  the  posterior  ear-like  part  is  less 
distiiu-tly  limited.  The  English  specimens  are  not  sufficient  to  show  whether  the 
inefpmlity  of  the  valves  is  as  great  as  in  irOibigny's  figure. 

7//y(''.  —  Prof.  Boule  informs  me  that  d'Oibigny's  figures  are  restorations  based 
on  two  specimens  from  the  Barreiuian  of  Bettancourt.  The  types  are  in  the 
Natural  History  Museum,  Paris. 

Disfrihiition. — Lower  Greensand  (Fitton's  Bed  13)  of  Atherfield.  ITythe  l^eds 
of  Lympne.     Lower  Greensand  of  Nutfield. 

IXOCEIIAMUS,  Sp. 

A  few  specimens  of  Tnoceramvs,  not  sufficiently  perfect  for  description,  have 
been  found  in  the  Speeton  Clay  (zone  of  Belemnites  Idfi'nili.s)  and  in  the  Spilsby 
Sandstone  of  Holton  and  Acre  House. 


L\ocei;amus  Salomoni,  iVOrhifjny,  1850.     Plate  XLV,  figs.  3 — 7. 

1850.     Inoceramus  Salomoni,  A.  d'Orhujny.     Prodr.de  Pal.,  vol.  ii,  p.  13!*. 
1853.  —  —  F.J.PiddandW.Roux.     Moll.  Fo.ss.  Gros  vorts 

de   Gfiu-ve,    p.    5Ul, 
pi.  xlii,  fig.  3. 
1855.  —  —  G.  Coiteau.     Moll.  Foss.  de  rYonue,  p.  107. 

1869.  —  —  F.  J.  Pictet  ami  G.  Campkhe.      Terr.  Crtt.    Ste. 

Croix  (Mater.  Pal.  Suisse, 
ser.  5),  p.  109,  pi.  clx,  figs. 
5—8. 

Defrrijjtioii. —  Lcit  valve  inflated,  subquadrate,  very  inequilateral.  Length  and 
height  nearly  equal.  Anterior  half  of  valve  very  convex  ;  posterior  half  compressed. 
Anterior  end  of  valve  more  or  less  nc^arly  perpendicular  to  the  plane  l)etween  the 
valves,  and  concave  near  the  umlio.     I'mbo  anterior,  prominent,  pointed,  incurved. 

'  See  footuotc  on  p.  267. 

=  Compare  also  forms  des(ri))ed  bv  Schmidt  as  allied  to  /.  ne<,coniit'ii>'is,  'Mi'm.  Aead.  Iiii]..  Sei. 
St.  Petersb.,'  ser.  7,  vol.  xviii  (lS72),  pp.  155—161,  pi.  ii,  fig.  8,  pi.  iii.  figs.  6—9. 


264  CRETACEOUS   LAMELLIBRANCHIA. 

A  broad,  usually  shallow  sulcus  extends  from  l)elow  the  umbo  to  the  ventral  margin, 
where  it  produces  a  slight  sinuosity  ;  usually  the  sulcus  starts  at  some  distance  from 
the  umbo,  and  may  consequently  l)e  absent  in  small  specimens.  Ornamentation 
consists  of  small,  narrow,  somewhat  irregular  concentric  ribs,  separated  by  broad, 
shallow,  concave  interspaces. 

Affinities.- — This  species  is  related  to  T.  rnnccntrwus,  Parkinson,  but  is  dis- 
tinguished by  its  sul)quadrate  outline,  by  the  length  and  height  being  ueai'ly  e(iual, 
and  by  the  presence  of  the  sulcus. 

liemarl's. — All  the  specimens  seen  are  internal  casts  of  left  valves.  The 
examples  figured  by  Pictet  and  Roux  and  by  Pictet  and  Campichc  are  also  left 
valves. 

Tiipe. — D'Orbigny's  specimens  came  from  the  Alljian  of  Novion,  Clar,  Geraudot, 
and  Saint  FJorentin. 

lihtriJint'um. —  Miiiiuiullnfus  bed  of  Copt  l^oint,  Folkestone. 


Inoceramus  AXtiLR'us,  sp.  uov.     Plate  XLV,  figs.  8 — 10.     Text-tig.  2l,i. 

1822.     Inoceramus,  sp.,  G.  Mantel!.     Foss.  S.  Ddwus,  ]i.  S>6,  jiI.  xix,  fig.  20. 
1859.  —  Crispii,   T.    Wiltshire.      The  Red  Chalk  of   Englaucl   (Geol. 

Assoc),  p.  16,  pi.  i,  fig.  4. 
1875.  —  coNCENTRicus,  A.  J.  Jukes-Browne.    Quart.  Jouru.  Geol.  See, 

vol.  .\.\xi,  p.  299. 

T)escrij)lh>n. — Shell  equivalve  or  nearly  equi valve,  very  inequilateral.  Anterior 
part  of  shell  convex,  the  convexity  decreasing  with  age ;  posterior  part  com- 
pressed, flattened.  Anterior  slope  of  valves  steep.  Anterior  margin  moderately 
convex  ;  ventral  margin  very  convex ;  posterior  margin  curved,  and  forming  an 
obtuse  angle  with  the  hinge-line.  Length  of  hinge  equal  to  rather  more  than  a 
third  of  the  height  of  the  shell.  IJmbones  nearly  terminal,  with  a  small  anterior 
curvature. 

Ornamentation  consists  of  strong,  regular,  concentric  ribs,  which  have  a  sub- 
sj'mmetrical  curvature,  and  become  less  distinct  on  the  posterior  flattened  part  of 
the  shell.  The  ril)s  have  rounded  summits,  and  are  separated  by  broad  rounded 
furrows  with  symmetrical  slopes.  Some  of  the  I'ibs  bifurcate,  some  maybe  dis- 
continuous, or  new  I'ibs  may  be  intei'calated. 

Affinities. — The  equal  size  of  the  valves,  the  greater  convexity  of  the  curve  of 
the  ril)s,  the  convex  form  of  the  anterior  margin,  and  the  outward  slope  of  the 
anterior  part  of  the  valves  distinguish  this  species  froai  7.  neocomieiisis,  d'Orbigny 
(p.   2(i2). 


INOCERAMUS. 


265 


I.  amilicus  also  resembles  /.  Ewaldl,  Scliliiter,'  l)iit  is  ivliitively  lii.ulici-,  iiinrc 
inequilateral,  and  the  ribs  are  more  strongly  curved. 

li'riiiarJcs. — This  species  has  been  usually  ideutified  as  /.  (■(Diceiifricns,  I'arkinsun, 
but  the  equal  size  of  the  valves  and  other  characters  readily  distinguish  it  from 


,-<*<"' 


Fig.  29. — Inoceramus  angliais,  sp.  nov.     Red  Limestone,  Hunstanton.     Sedgwick  Museum, 
Cambridge.    Part  of  right  valve.     Natural  size. 

that  species.     An  example  from  Hunstanton  was  figureil  l)y  Wiltshire  as  /.  CrUpii 
(=  Crippsi),  Mantell. 

Distribution. — Red  Limestone  of  Hunstanton.  Gault  of  Folkestone.  Cam- 
bridge Greensand  (derived  from  the  Gault).  Marl  in  the  Gault  of  Roydon,  West 
Norfolk.     Upper  Greensand  of  Haldon,  the  Isle  of  Wight,  and  Devizes. 


liNouiiKAMUs  coxciiNTiucus,   Pd rlcinxitii,   181'.l.     Plate  XLV,   fig.   11;    Plate  XLVI, 

figs.  1  —  10  ;  Plate  XLVII,  figs.  1,  2. 

1819.     iNOCERAMtrs  coNCENTRicus,  J.  ParJii iinon .     Trans.  Geo!.  Soc,  ser.  1,  vol.  v, 

p.  68,  1)1.  i,  &g.  4. 

1821.  —  —  J.  Sowerhij.     Miu.  Couch.,  vol.  iii,  p.  183,  pi. 

cccv,  figs.  1  —  6. 

1822.  —  —  G.  Manlell.     Foss.  S.  Downs,  p.  95.  pi.  xix, 

fi-s.  15,  19. 
—  —  —  A.  Broiignlart  in  Curler.       Ossemens    Foss., 

vol.  ii,  pt.  2,  pp.  333,  33(5. 
609,  pi.  vi.  fij,'.  11. 
1828.  —  ORTPH.«:oiDES,  J.  de  C.  Sowerby.     Jliu.  Coneb  ,  vol.  vi,  p.  161, 

pi.  illwxiv.  fijx.  1. 


1  See  footnoU'  on  p.  267. 


266  CRETACEOUS   LAMELIJBEANCHIA. 

1833.     Catili.i's  ptkiformir,  H.  Muhclin.     Ma<,'asin  do  Z<i()]ni;i(\  iii,  Classo  5,  pi. 

xxxii. 
183C.     Inocekamu.s  concentricus,  A.   GoIiI/hsk.     Petref.  Gonii.,  vdl.  ii,  p.   Ill, 

pi.  cix,  fi<;s.  8'/,  b,  c,   (uon 
8d,  e,f). 
?  1842.  —  —  P.  M,tt](n-(,n.      Catal.  Foss.  des  Bouches-du- 

Rlionc,  p  173. 
184C.  —  A.  iVOrhujnij.     Tal.  Franc.  Terr.  Crct.,  vol.  iii, 

p.  50fi,  pi.  cccciv. 

—  --  —  ^t.  Lci/iiicfii'.      Statist,  geol  et  niiii.  do  rAube, 

Atlas,  pi.  V,  fi'^.  12. 
1850.  —  --  H.B.Geinitx.    Das  Quadorsandst.  oder  Kreide- 

j;ol).  ill  Dontsclilund,  p.  174. 

—  —  ~  A.  iVOrhUjny       Prodr.  de  Pal.,  vol.  ii,  p.  138. 
18.53.              —                      —  F.  J.  Piclet  ami  W.  Eoux.      Moll.  Foss.  Gros 

verts  de  Geneve,  p.  500, 
pi.  xlii,  &g.  2. 

1854.  —  --  J.Morris.      Cat.  Brit.  Foss.,  cd.  2.  p.  ItSP. 

—  —  ORYPH^EOiDES,  /.  Jl/oms.     Ibid.,  p.  169. 

1855.  —  CONCENTEICTTS,  G.  Cottcau.     Moll.  Foss.  de  I'Toune,  p.  1(»7. 
186<).               —  —  F.  J.  Piciet  ,1,1,1  G.  Cminchc.     Terr.  Cn't.  Ste. 

Croix  (Mator. Pal. Suisse, 
ser.  5),  p.  107. 

1876.  —  —  J.  F.Whiteiivrs.   Mesozoic  Fossils  (Geol.  Surv. 

Canada),  vol.  i,  pp.  79,  241. 

1877.  -■  —  C.  Schliifer.      PalfEoutographii-a,  vol.  xxiv,  p. 

255. 

—  —  —  G.  Bi'ilim.    Zoitsehr.  d.  deutscli.  Lfool.  Gesellscli., 

vol.  xxix,  p.  238. 
1897.  —  It.  B.  Newton.      Proe.  Dorset  Nat.  Hist,  and 

Antiq.  Field  Club,  vol.  xviii, 
p.  88,  pi.  iii,  fig.  12. 
1906.  —  A.  Wollenvmn.      Jalirb.    d.    k.    preuss.    geol. 

Laudesaust.  fiir  1906,  vol. 
xxvii,  p.  271. 

Non  1837.  —  —  G.  Fischer  de  Waldheim.     Orvctogr.  de  Mos- 

cou,  p.  177,  pi.  XX,  figs.  1 — 3. 
(=  Aucella  Keyserlitigiana, 
Trautschold). 

—  Ibl41.  —  —  F.  A.  Iti'micr.      Die   Verstein  d.  uord-doutsoli. 

Kroidegeb.,  p.  61. 
-—    1845.  —  -  E.  Forbes.      Quart.    Journ.  Geol.   Soc,   vol.  i, 

p.  247  (/.  iii'ocomii-ii)!i.>\  d"Orb.) 

—  1846.  —  — ■  A.  E.  Reuss.     Die  Verstein.  der  iiilhni.  Kroide- 

forniat.,  pt.  2,  p.  24 

—  1847.  —  —  J.  Midler.     Pelref.  der  Aaolion.  Kroidef..  pi.  1, 

p.  30. 


INOCERAMUS.  2G7 

Noil  1875.     Inoceeamus  concentricus,  A.  J.  Jukes-Browne.     Quart,  Jouni.  Gcol.  Soc, 

vol.  xx.\i,  p.  21)9. 

Desciiplinii. — Slicll  iniiiv  or  less  ovaic,  much  liii^-licr  tliaii  long,  vei'v  iii('(|iii- 
lateral  and  ineqnivalve.  Anterior  part  of  valves  flattened  or  concave,  often  more 
or  less  nearly  perpendicular  to  the  plane  between  the  valves.  Posterior  part  of 
the  valves  somewhat  expanded  and  less  convex  than  the  part  below  the  uml)ones. 
Postero-dorsal  part  forming  a  small  wing.  Left  valve  very  convex,  Avith  a  high, 
nai'ruw,  pointed,  terminal  uniljo  which  is  considerably  incurved  and  bends  forwards. 
Right  valve  considerably  less  convex  than  the  left  valve,  with  a  small,  terminal 
umbo  curved  forwards  but  only  slightly  inwards.  Hinge-line  less  than  half  the 
height  of  the  shell. 

When  the  shell  is  perfect  the  surface  is  nearly  smooth  except  for  nuTuerous 
ivgular  growth-rings.  When  the  outer  layer  of  the  shell  is  wanting  concentric 
undulations  or  ribs  having  an  unsymmetrical  curvature  are  seen,  and  are  separated 
by  concave  furrows. 

Affinities. — /.  concctifriciM  has  been  compared  l)y  Wolleniaun  with  7.  Val-oIiH, 
Schli'iter,^  but  the  prominent  umbo  and  other  characters  readily  distinguish  it  from 
that  species.     See  also  I.  cuncentricus  var.  snbsHlcatuf,  and  I.  snlcatn.<!  (below). 

liemarJcs. — Whilst  the  left  valve  in  the  specimens  from  the  Blackdown  Greensand 
agrees  closel}-  with  that  of  specimens  found  in  the  Gault,  the  right  valve  in  many 
(but  not  all)  cases  is  relatively  moi-e  convex,  especially  between  the  umbo  and  the 
postero-veiitral  extremity,  and  the  ribs  are  more  sharply  cui'ved.  A  similar 
modification  is  seen  in  the  examples  from  the  Red  Limestone  of  Hunstanton.  'J'liere 
seems  no  reason  for  regarding  the  specimens  with  these  characters  as  forming 
more  than  a  local  variety  dependent  on  the  fact  that  they  lived  muler  conditions 
different  from  those  Avliich  prevailed  where  the  Gault  was  deposited. 

/.  r/ri/plicCuichs,  Sowerby,  was  founded  on  an  internal  cast  of  /.  i-oiirnitrirns 
from  the  Upper  Greensand  ;  in  such  casts  the  ribs  are  more  prominent  than  on 
the  surface  of  the  shell  itself. 

All  the  examples  from  the  Candjridge  Greensand  which  have  been  recorded  as 
I.  coiiccnfricKs  ai)j)ear  to  l)elong  to  1.  aiir/licii-s  (p.  2(1 1). 

Tijpes. — The  type,  which  came  from  the  Gaidt  of  Folkestone,  cannot  now  be 
found.  The  specimens  from  the  same  locality  figured  by  Sowerby  and  by  ]\hintel!, 
and  the  type  of  /.  ijnjphxo'ules  from  the  Upper  Greensand  near  hyiiu'  Rt-'gis,  are  in 
the  Hiitish  ^luseum. 

Didiiliatinii. — In   all   zones  of  the  (iault  of  Folkestone.      (!ault  of  Aylesford, 

1  'Mouatsber.  d.  k.  piviiss.  Aka.l.  Wissenscli.,  Birliu'  (18(30),  p.  345.  Schlutor,  '  Piiliuonto- 
iji-.ipliicii,'  vol.  .\xiv  (1877;,  p.  255.  Wollomaim,  *•  Bivalv.  u.  Gastiop.  J.  iiorddeutSL-h.  Gaults" 
(' Jaliil).  d.  K.  prciiss.  geol.  Laudesaust.,'  vol.  .\.\vii,  1900),  p.  272,  pi.  vi,  fig.  9. 


2G8  CRETACEOUS   LAMELLIBRANCHIA. 

Dunton  Green  (Kent),  Black  Yen,  and  Okeford  Fitzpaine.  Upper  Greenland 
(zone  of  Schlcenhachia  rosirata)  o^  Blackdown,  Sidmoutli,  Lyme  Regis,  and  Potterne 
near  Devizes.  Limestone  in  tlie  Gault  of  AVe.st  Bilney,  Roydon,  and  Grimston 
(West  Norfolk).     Red  Limestone  of  Hunstanton. 

Inoce1!.\mu.s  coNCKNTiiicrs  var.  sriiSLTi.f'ATi'S,   WilUhiri',  1869.     Plate  XfiVII,    figs. 

3—14. 

1853.     Inoceeamus  svt.cA-rvs,  F.  J.  Pictcf  and  W.  Ronx.     Mull.  Fos.s.  Grcs  verts 

de  Geneve,  p.  499,  pi. 
xlii,  figs.  1  d,  e,  /. 

1869.  —  svbsvIjCatvs,  T.  Wllfyh ire.     Quart.  Jouru.  Geol.  Soc.,  vol.  xxv, 

pp.  188.  190. 

1879.  —  —  F.  Cf.  H.  Pm-r.     'Ihe  Gault,  p.  54. 

In  the  lowe.st  zone  of  the  U])per  (iuult  there  occur  tornis  of  Lioccrainns  which 
differ  from  I.  concentricus  only  in  the  fact  that  radial  plications  are  more  or  less 
extensively  developed.  Li  these  forms  every  stage  can  l)e  traced  l)etween  /.  con- 
centricus without  plications  into  forms  in  which  the  plications  are  almost  as 
complete  as  in  /.  snlrnfiis.  A  specimen,  which  differs  from  I.  concent ricns  only  in 
the  occurrence  of  one  shallow  plication,  is  shown  in  fig.  3  (Plate  XLVII)  ;  others 
are  similar,  hut  jiossess  two  or  three  plications  (Plate  XLVII,  figs.  4,  5).  In  most 
cases  the  early  ])art  of  the  shell  agrees  entireh'  Avith  I.  concentricus ;  but  the 
duration  of  this  stage  varies  considerably  in  different  individuals,  and  sooner  or 
later  either  a  few  or  many  plications  are  developed.  When  the  plications  are 
numerous  and  start  from  near  the  umbo  the  shell  closely  resembles  I.  sulcntnx, 
but  may  usually  be  distinguished  by  the  rounded  (instead  of  angular)  form  of 
the  plications,  and  by  the  presence  of  concenti'ic  ribs.  For  these  forms,  which 
characterise  a  definite  horizon  in  the  Gault,  it  will  be  convenient  to  adojjt  as  a 
varietal  designation  the  name  suhsnlcatns,  given  by  Wiltshire  in  18(59. 

From  a  study  of  many  forms  of  this  A'ariety  it  seems  evident  that  /.  snlmtus 
lias  been  derived  from  /.  concrntricns  by  the  grailual  di'velopment  of  plications,  and 
this  view  is  in  accordance  with  stratigraphical  distribution,  since  /.  concent ri ens  is 
the  earlier  of  the  two  species,  being  found  throughout  the  Gault,  whilst  7.  snJcatns 
occurs  in  the  upper  })art  of  the  Gault  only. 

If   7.   snlcatns  has  been    dei'ived   from  I.  coiicentricn.s,  then    it  is  clearly  more 

nearly  related  to  that  than  to  any  other  species  of  Inoceramus,  and  cannot  therefore 

1)0  placed  in  a  separate  genus  or  suli-genus  [Aetinoeennnnx),  as  was  proposed  by 

Meek.'     l"'urthef,  in  the  early  stages  of  the  \i\v\vty  sn1>snlcatns  the  shell  is  a  typical 

1  '  Clieek  List  Ciet.  Foss.  N.  Amer.'  (' Suiitliscu.  Miscell.  Coll.,'  No.  17",  1864),  p.  32.  Stoliezka, 
'  Cret.  Fauna  S.  India,' vol.  iii  (1871),  p.  393.  Meek  and  Haydeu,  '  Invert.  Cret.  Tert.  Foss.  U. 
Missouri'  (1876),  p.  39. 


INOCERAMUS.  209 

l-iioceramnx,  l)iit  subsequently  it  possesses  the  chai'actcrs  of  Arlinorerniinis.  Also 
it  appears  that  a  somc^Yllat  similar  plication  has  originated  independently  in  I. 
Salumoni  (p.  263),  and  probably  too  in  1.  radians,  Schli'itei','  and  1.  fascial  as,  Miiller." 

Pictet  and  Roux  I'egarded  snhKuIcatiis  as  a  variety  of  /.  milratus  in  ■which  the 
number  of  plications  had  decreased ;  the  stratigraphical  distriljution  and  also  the 
evidence  of  the  extensive  series  of  specimens  of  .suhsiilcahis  which  has  now  been 
obtained  are  opposed  to  this  view. 

Distrihittioii. —  Lowest  zone  of  the  Upi)er  Gault  of  Folkestone.  Upper  Green- 
sand  of  Blackdown.     Red  Limestone  of  Hunstanton. 

Inocekamds  sulcatus,  rarliusou,  1819.     Plate  XLVII,  figs.  15—20. 

1819.     Inocekamus  svj^catvs,  J.  Parkinson.     Trans.  Geol.  Soc.ser.  1,  vol.  v,  p.  .50, 

pi.  i,  fit;;.  5. 

1821.  —  —       J.  Sowcrliij.     Mill.  Conch.,  vol.  iii.  p.  184,  ])1.  ccevi, 

figs.  1 — 7. 

1822.  —  —       G.  Matitell.     Foss.  S.  Dowus,  p.  95,  pi.  xi.x,  fig.  16. 
—                  —                   —       A.  Brotiijniart  in  Citvier.     Osscinens  Foss.,  vol.  ii, 

pt.  ii,  j.p.  333,  336,  pi.  vi,  fig.  12. 

1836.  —  —A.  Gohlfms.     Petruf.  Gonn.,  vol.  ii,  p.  112,  ].l.  ex, 

fig.  1. 

1837.  —  —       W.  Hi.<iii</rf.     Lethsea  Suecica,  p.  56,  pi.  xvii,  fig.  9. 
1846.  —       A.  (VOrhiijrnj.     Pal.  Fianr.  TeiT.  Cret.,  vol.  iii,  p.  504, 

[.l.  ccctiii,  figs.  3  —  5. 
1850.  —  —       A.frOrhlijtiij.     Pimlr.  de  Pal.,  vol.  ii,  p.  139. 

1853.  —  —       F.  J.  Piclet  and  W.  liuiLi:     Moll.  Foss.  Grcs  verts  dc 

Geneve,  p.  499,  pi.  xlii, 
figs.  li(-c  (not  d-f). 

1854.  —  —J.  Morrie.     Cat.  Brit.  Foss.,  e.l.  2,  p.  170. 

1855.  —  —       G.  Cotleati.     Moll.  Foss.  de  I'Yonne,  p.  107. 

1864.     AcTiNOCERAMUs  scLCATUs,  F.  IS.  Meek.     Check   List  Ciet.  Foss.  N.  Amer. 

(Smithson.    Miscell.    Coll.,    No. 
177),  p.  32. 
1869.     Inocekamus  stjlcattjs,  F.  J.  Ficlet  and  G.  Campiche.     Foss.  Terr.  Cri't. 

Ste.  Croix  (Mater.  Pal.  Suisse, 
ser.  5),  p.  105. 
1875.  —  —       A.  J.  Jiikcs-Broune.     Quart.  Jomu.  Geol.  Soc.,  vol. 

xxxi,  p.  298. 

1877.  —       C.  Schliiler.    Pala?ontogTapLiea,  vol.  xxiv,  j).  266. 

1884.  (AcTJNOCEBAMUs)    SULCATUS,  J.   F.    Whilcaiif.      Mcsozoic 

Fossils,  vol.  i  (Geol.  Siirv. 
Canada),  p.  241,  pi.  xxxii, 
fig.  3. 


1  '  Palttontographica,'  vol.  xxiv  (1877),  \>.  270.  pi.  iii,  fig.  2. 

2  '  Jahrb  d  k   i.rcuss.  gcol.  Landesansf.  ffir'  1887  (1888),  p.  416.  pi.  xviii,  fig.  3. 

30 


270 


CRETACEOUS   LAMELLIBRANCHTA. 


I'JOG.     Inoceramus  sulcatus,  ^4.  WoUcmann.  Jahrlj.  J.  k.  pruuss.  geol.  Landesanst. 

fiir  1906,  vol.  xxvii,  p.  273,  pi.  vi, 
%.  10. 


Noil  1827. 


S.  Nilsson.     Petrif.  Suecana,  p.  18. 


Dcscrlpliou. — Shell  more  or  le.ss   ovate,  mucli  liiglier  than  long,  very  inequi- 
lateral, more  or  less  considerably  inequivalve.     Anterior  j^art  of  valves  flattened 


Fia.  30. — Inoceramus,  s^.     Gault,  Folkestone.     Sedgwick  Museum,  Cambridye.     Internal  ciist  nf  liylit 

valve.      X  ^. 

or  concave.  Posterior  part  somewhat  expanded  and  loss  convex  than  the  part 
below  the  umbones.  Left  valve  very  convex,  with  a  liigh,  narrow,  pointed 
anterior  umbo  which  is  considerably  incurved  and  bends  forwards.  Right  valve 
rather  less  convex  than  the  left  valve,  with  a  smaller  umbo  whicli  bends  forwards 
and  slightly  inwards. 

Ornamentation  consists  of   strong  angular   radial  ridges  ([)lications),  usually 
from  eight  to  ten  on  each  valve,  which  are  often  unequal  in  size  and  are  separated 


mOCERAMUS.  271 

liy  deep  furrows.  The  ridges  are  often  at  unequal  distances  from  one  another; 
some  of  them  start  from  the  umbo,  others  may  be  intercalated  or  may  arise  by 
bifurcation.  Fine  concentric  lines  cover  the  shell  and  are  folded  where  they 
cross  the  ridges  and  furrows. 

Affinities. — Although  the  radial  plications  give  a  distinctive  appearance  to  this 
species,  yet  the  form  of  the  shell  closely  resembles  that  of  I.  concentvicuH,  the  main 
difference  being  that  in  the  former  the  difference  in  the  convexity  of  the  two  valves 
is  usually  less  marked  than  in  the  latter. 

Types. — The  type,  from  the  Gault  of  Folkestone,  is  in  the  British  Museum. 
The  specimens  from  near  Lewes,  Folkestone  (except  figs.  1  and  2),  and  Clophill 
figured  by  Sowerby,  and  the  specimens  figured  by  Mautell  are  in  the  British 
Museum. 

.Distribution. — Gault  of  Folkestone,  Aylesford,  Ringmer,  Eastbourne,  the  Isle 
of  Wight,  and  Leighton  Buzzard.  Upper  Greensand  (zone  of  Schlcenbuchia 
riistrai(i)  of  Blackdown,  Sidmouth,  Black  Yen,  and  Lulworth.  Red  Limestone  of 
Hunstanton,  South  Willingliam  (Lincolnshire),  and  Speeton. 

Inoceramus,  sp.     Text-fig.  30. 

Specimens  of  a  large,  slightly  convex  Inoceramus  are  found  in  the  Gault 
of  Folkestone  and  the  Upper  Greensand  of  Potterne  (Devizes)  and  the  Isle 
of  Wight,  but  are  not  sufiiciently  perfect  for  determination.  The  umbones  are 
terminal,  and  the  hinge-line  is  nearly  at  right  angles  to  the  anterior  margin.  The 
anterior  parts  of  the  valves  slope  steeply  to  the  margin.  Small  and  rather 
distant  concentric  ribs  are  present.  This  form  shows  some  resemblance  to  I.  jj/V7«,s 
(p.  279),  but  is  less  convex,  and  possesses  fewer  ribs. 

Inoceeamus  tenuis,  Mavtcll,  1822.     Plate  XLVIII,  fig.  J.     Text-figs.  31,  32. 

1822.     Inoceramus  tenuis,  G.  Manfell.     Foss.  S.  Downs,  p.  132. 
1854.  —  —J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  170. 

?  1859.  —  —       r.  Wiltshire.     Eed  Chalk  of  England  (Geol.  Assoc), 

p.  16,  pi.  i,  fig.  5. 
186(5.     Peena  lissa,  II.  G.  Seeley.     Auu.  Mag.  Nat.  Hist.,  ser.  3,  vol.  xvii,  p.  178. 

Non  1841.      Inoceramus    tenuis?    F.    A.    Enmer.      Pie   Verstein.   d.   nord-dcntscli. 

Kreidegeb.,    p.     62,    pi.    viii, 
fig.  11. 

De.srr?/)//o/(.— Shell    inequivalvo,    very    inerpiilateral,    convex  ;     postero-dorsal 
part  compressed  ;  antero-dorsal  pait  excavated  and  more  or  less  nearly  perpen- 


272 


CRETACEOUS   LAMELLIBRANCHIA. 


diculai-  to  tlie  plane  of  the  valves;  height  greater  than  length.  Hinge-line  equal 
to  a])out  two-thirds  of  the  height  of  the  shell.  Ventral  margin  very  convex; 
posterior  margin  forming  an  obtuse  angle  with  the  hinge-line.  Umbones  terminal, 
curved  inwards  and  forwards,  the  left  umbo  larger  and  more  prominent  than  the 
right.     Surface  smooth,  except  for  growth-rings. 

Affinities. — /.     tennis    resembles    7.    roncentricus,   but    the   left    umbo    is    less 


Fio.  SI.— Inocerumns  tenuis,  Mantcll.  Chalk  Marl,  Hamsey.  Tlio  typo.  No.  5SUU,  BrUisli  iMiiscum  (Nat. 
Hist.).  The  specimen  is  sumewliat  c-niiipiessod  from  front  to  back.  Left  valve  and  anterior  view  of  both 
valves.     Kiijht  valve  shown  in  the  next  fiijure. 


prominent,  the  length  of  the  shell  is  relatively  greater,  and  tlie  concentric  rings 
are  less  prominent. 

The  fragmentary  specimens  described  by  Seeley  as  I'mtu  lisaa  a[)pear  to  belong 
to  this  species.' 

Ti/i,cs.—Jn  the  Britisli  Museum  (No.  589(»)  from  the  Chalk  .Marl  of  Hamsey. 
A  fragment,  from  the  Red  Limestone  of  Hunstanton,  which  appears  to  l)e  one  of 

^  Tlie  form  from  tlie  Kcd  Limestone  of  Hunstaiiton  wLieli  wa.s  named  Fcniii  Ininnrffsa  bv  Seeley 
is  at  present  known  only  liy  an  imjiorfeel  left  valve.  It  is  perhaps  allied  to  /.  (ftmis,  but  is  remark- 
able in  beiny  mueli  lonijei'  than  IiIl;!).  The  ty|ie  is  m  the  Sedgwick  Mu.seiiiii,  Canibriilge.  Seeley, 
'Auu.  Mag.  Nat.  Hist.,'  .ser.  ,!,  vol.  .wii  (Ib'OG),  p.  1711. 


INOCERAMUS. 


273 


the  specimens  on  which  Soeley's  dosciMption   of   Pcnni  Ussk  was  l)fise(l,  is  in  the 


Sedgwick  Museum,  Canibridgc 


V 


Fio.  32. — Iiioceramws  fi'n » is,  Mantell.     Rij4;lit  valve.     See  Fig.  31. 

D'islrlhntion. — Red  Limestone  of   Hunstanton,    Loutli,    and   Speeton. 
Greensand  of  Ventnor  and  Pottei-iu'.      f'lialk  ^rui-l  of   llaniscv. 


Upper 


Inooeramus-  Crippsi,  Mantell,  1822.     Plate  X  1;V1 1 1,  tigs.  2,  :5.     Text-figs.  33—35. 


1822.     Inoceramus  Cbipsii,  G.  Mantell.     Fo.ss.  S.  Dowus,  p.  133,  pi.  xxvii,  dg.  11. 
1836.  —  LATUs,  A.  Gohlfuss.     IVtref.  trfriu.,  vol.  ii,  p.  117,  pi.  cxii, 

fig.  5  (non  Mantell). 
1846.  —A.  d'Orhujivj.     P.il.  Franc.  T.rr.  Crot.,  vol.  iii,  p.  513, 

pi.  ccccviii,  figs.  1,  2. 
18.54.  -  Crisi'ii,  J.  Morris.     Cat.  Brit.  Foss..  ed.  2,  p.  169. 

190t.  —  LATUS,  E.  T.  Neirtoii   an  I  A.  J.  JiiJceg-Broime.       In    Jukes- 

Browue,Cret.  Eocks  of  Britain, 
vol.  iii,  p.  449. 
1909;  CitiPi'sr,  J.  fiiihm.     Subhercyn.  KreiJemuldi.-  (Abhamll.  d.  k. 

prou.ss.    <;eol.    LauJosanst..    n.f.,    5t>), 
p.  41,  1)1.  ix,  fig.  1. 


274  CRETACEOUS    LAMELLIBRANCHIA. 

Non  1822.     Inoceeamtjs  latus,  G.ManlfU.     Foss    S.  Downs,  ]>.  21G,  pi.  xxvii,  fig.  10. 

—  1828.  —  —      /.    de  C.    Sowerhj.     Min.  Couch.,  vol.  vi,  p.   159,  pi. 

dl.xxxii,  fig.  1. 

—  1836.  -  Ciuspii,^.Go7((A'»«.  Petref.  Gfim.vol.  ii,p.  116,pl.cxii,fig.4. 

—  1840.  —  —       H.  B.  Geiiiitz.     Char.  d.  Scliicht.  u.  Petref.  des  siichs. 

Kreidfgob.,  pt.  1,  p.  27. 
1841.  —  i-xTva,  F.  A.  Eomer.  Die  Versk'in.  d.  uord-deutsch.  Kreidegeb., 

p.  61. 

—  —  —  Cripsii,  RiJmer.     Ibid.,  p.  03. 

—  1846.  —  —       H.  B.  Gfiiiilz.     Gruudr.  d.  Versteiu.,  p.  464. 

—  —  —  LATUS,  Geinilz.     Ibid.,  p.  463. 

—  —  —  —     A.  E.  Reiiss.     Die  Versteiu.  der  bohin.  Kreidei'onuat., 

pt.  2,  p.  25. 

—  —  —  C EiPSii,  Ite(s«.     Ibid.,  p.  25,  pi.  xxxvii,  figs.  10,  12. 

—  1847.  —  —       J.  Midler.     Pelref.  der  Aachen.  Kreidef.,  pt.  1,  p.  30. 

—  1852.  —  —       F.  Romer.     Kreidebild.  v.  Texas,  p.  56,  pi.  vii,  fig.  2. 

—  —  —  LATus,  Riiitier.     Ibid.,  p.  60. 

—  1859.  —  CRispn,T.  Wiltshire.     Eed  Chalk  of  England  (Geol.  Assoc.), 

p.  16,  pi.  i,  fig.  4. 

—  1863.  —  Crifsi,  A.  V.  St loiiiberJi.     Zeitschr.  d.deutscb.  geol.  Gesellsch., 

vol.  XV,  p.  152. 

—  1866.  —  —        K.  A.  ZilteJ.     Bivalv.  d.  Gosaiigeb.,ii(Denkschr.  d.  k. 

Akad.  Wissensch  ,  Wien,  Math.-iiat. 
Ci.,  vol.  xxv),  p.  95,  pi.  xiv,  figs.  1 — 5, 
pi.  XV,  figs.  1 — 5. 

—  —  —  LATUS,  Zittel.     Ibid.,  p.  100,  pi.  xiii,  fig.  7. 

—  1869.  —  CniFni,  E.  Favre.     Moll.  Foss.  de  la  Craie  de  Lemberg,  p.  132. 

—  1870.  —  i^ATVS,  F.  Rlimer.     Geol.  Oberschles.,  p.  316,  i)l.  xxxiv,  fig.  12. 

—  —  —  Cripsii,  Rlimer.     Ibid.,  p.  356,  pi.  xxxix,  fig.  9. 

—  1871.  —  CuispiANUs,    F.    Stoliczka.       Palaeont.    ludica,   Cret.    Fauna 

S.  India,  p.  405,  pi.  xxvii,  figs. 
1 — 3,  pi.  xxviii,  fig.  2  (not  pi. 
xxvii,  fig.  3, 1.  Heherti,  Fallot). 

—  1872.  —  Cripsi,   H.  B.  Geliiih.       Das  Elbthalgeb.  in  Sachsen   (Pal- 

seontographica,    vol.    xx,    pt.    2), 
p.  49,  pi.  xiii,  figs.  11-15. 

—  —  —  LATUS,  Geinitz.     Ibid.,  p.  45,  pi.  xiii,  figs.  4,  5. 

—  1873.  —  —     Geinitz.     Neues  Jahrb.  fiir  Miii.,  etc.,  p.  11. 
— •      —  —  Cripsi,  Geinitz.         Ibid.,  p.  16. 

—  1875.  —  LATUS,  C.  Di'cocq.     Assoc.  Fran^.  Avane.  Sci.  (Lille),  p.  369. 

—  1876.  —  Critsii,  D.  Branns.     Zeitschr.  f.  d.  gesammt.  Naturwissensch., 

vol.  xlvi,  p.  378. 

—  —  —  ^        ?  var.  Bababini,  F.  B.  Meek.       Invert.  Cret.   Tert. 

Foss.  U.  Missouri,  p.  49,  pi.  xii,  fig.  3,  pi.  xiii,  fig.  1 . 

—  • —  —  —        ?  var.  subundatus,  J*.  2?.  Jl/ee.'.-.     Bull.  U.S.  Geol.  and 

Geogr.   Surv.   'J'erritories,  vol.  ii,  p.  358,  pi.  iii, 
figs.  1,  3. 


—  1882.  — 

—  1885.  _ 


INOCERAMUS.  o-- 

Nou  1877.     iNOCEE.vMus  Cripsii,  C.  Srhlnter.     Pala^ontographica,  vol.  xxiv,  p.  277 

18/8.  _  I.ATUS,    C.  Ban-ois.      Ann.  Soc.  gcol.   Nord,  vol.  'v,   pp.    407, 

475. 

—  1879.  —  Ckipsii,  vars.  pboximus,  suciensis,  Bakabini,  /.  F.  Wkiteaves. 

Mesozoic  Foss.,  vol.  i  (Geol.  Surv. 
CaiKula),  j.p.  172—174. 
—       H.  Schroder.     Zeitschr.  d.   doutsch.  geol.  Gesellscli., 
vol.  xxxiv,  p.  273. 
Ceipsi,  E.  Fallot.     Ann.  Sci.  gool.,  vol.  xviii,  p.  250. 

-  1887.  -  CuiPsii,  A.  Peron.     Hist.  I'err.  Craie  S.E.  du  B.issin  Anglo- 

Parisien,  p.  158. 
~   ^^^^-  ~  —        G.  Mnller.     Jahrb.  d.  k.  preuss.  geol.  Laudesaust.  fur 

1887,  p.  416. 
1889.  —  ~       E.  Holzapfel.     Die  Mollusk.  Aachen.  Kreide  (Palseon- 

togniphica,  vol.  xxxv),  p.  222. 
~      ~  ""  Gmvsi,  A.  Fritsch.       Stud,  i.u    Gehiete   der  bOliin.   Kreide- 

format.,  iv,  Teplitz.  Schicht.,  p.  82,  fig.  73. 
~     ~  ~  ~       0.    Grlepenkerl.      Seuon.    v.    Kouigslutter  (Piil»ont. 

Abbaudl.,  Vol.  iv),  p.  50. 

—  1891.  —  Cripsii,  /.  Bohm.     Palaeontographica,  vol.  xxxviii,  p.  81. 
1892.             —  ~       K.  FnUerer.     Ober.  Kreidebild.  St.  Croce  (Palaiont. 

Abhandl.,  vol.  vi),  p.  80. 
~      ~  ~  Ckipsi,  E.    Stol/ey.      Kreide    Schleswig-Folsteius    (ilittheil. 

Min.  Instit.  Universit.  Kiel,  vol.   i), 
p.  241. 

—  1894.  —  Ckippsi,  B.  Lundgreii.     Mammilatus  och  Mucrouatu  zouema 

(K.    Svenska    Vet.-Akad.    Hindi., 
N.F.,  vol.  xxvi,  No.  6),  p.  45. 

—  1897.  —  Cripsii,  R.  Leonhard.     Pateoutographica,  vol.  xliv,  p.  49. 

—  —  LATUS,  Leonhard.     Ibid.,  p.  49. 

—  1898.  —  Ciirp.iii,  G.  iHnier.     Mollusk.   Uuterseu.   v.  Braunschweig  u. 

Ilsede    (Abhandl.    d.  k.  preuss.  geol. 
Landesanst.,  n.f.,  25),  p.  45,  fig.  12. 

—  1899.  —  —       Q_de  Alessandri.     Palaeont.  Ital.,  vol.  iv,  p.  194,  pi. 

xvi,  fig.  9. 

—  —  —  LATUS,  Alessandri.     Ibid.,  p.  196. 

—  1900.  —  Cripsi,  a.  Wollemann.    Jahrb.  d.  k.  preuss.  geol.  Landesanst. 

fiir  1900,  vol.  xxi,  p.  18. 

—  1901.  —  LATVs,  F.  Sturm.     Ibid.,  vol.  xxi,  p.  93,  pi.  x.  fig.  2. 

—  Ceipsi,  H.  Imkeller.     Palaeontographica,  vol.  xlviii,  p.  33. 

—  1902.  —  _      var.  eadiosa,  A.  Qitaas.      Ibid.,  vol.  x.\x,  2.  p.   170. 

pi.  XX,  figs.  9,  10. 

—  —      -4-    Wollemann.      Luneburg.  Kreide   (Abhandl.  d.  k. 

preuss.    geol.    Laudesaust.,    n.f., 
37),  p.  72. 

—  1903.  —  LjLivs.W.Petratcheck.   Jahrb.  d.  k.  fc.  geol.  Rvi.hsanst.,  vol.  iiii, 

p.  165. 


276 


CliETACEOUS   LAMELLIBKANCHIA. 


Noil  11105.     Inockramus  Cripsi,  T.   Weyuer.     Zoiisclir.    J.    Joutscli.   geul.    Gesellscli., 

vol.  Ivii,  p.  161. 

—  1906.  —  Crispianus,  /.  PelhiJ.     Palseontograpliicii,  vol.  lii,  j).  l'32. 

—  1908.  —  Cripsii,  a.  StojaiKiff.     Ann.  gi'ol.  min.  Russie,  vol.  x,  p.  121. 

Descr'ipiio)!. — Shell  thin,  (Miuivalve,  inodenitely  inequilateral,  convex  between 
the  umbo  and  the  vential  margin  ;  postcro-dorsal  part  compressed  and  flattened  ; 
antcro-dorsal  marginal  part  ncaih'  jieijicndicular  to  the  plane  of  the  valves  and 

Fig.  33. 


Fio    .34. 


Fia.33.— J«oferami(s  Cripyii^i.  Maiitfll.  Tlic  tyiu^,  Biitisl.  Mu.seum  (Nat.  Hist.)  No.  o8y3.  Chalk  Marl, 
Oft'hnin.     IntiTiinl  cast.     Natural  size.  .... 

Fio.  -i-l.—Inocerarnvs  Crippsi,  Mantoll.  Clialk  Marl.  Internal  cast  of  a  left  valve  similar  to  the  type. 
British  Museum  (Nat.  Hist.)  No.  589.5.     Natural  size. 

nearly  straight.  Ventral  margin  convex  ;  posterior  margin  only  slightly  convex, 
aiul  forming  more  than  a  right  angle  with  the  hinge-line.  Hinge-line  forms  an 
angle  of  about  1  10"  with  the  antero-dorsal  margin.  Umboncs  inconspicuous, 
pointed,  not  curved,  at  about  a  third  of  the  length  of  the  hinge  from  the  anterior 
end  ;  in  front  of  the  umbones  is  a  small,  obtusely  triangular  ear. 

Ornamentation  consists  of  broad,  rounded,  rather  iiii'gnlar  concentric  ribs, 
which  are  strong  anteriorly,  and  liecoine  weaker  posteriorly.  The  curvature  of 
the  ribs  is  unsymmetrical  ;  the  anterior  part  curves  raiiidly,  the  po.stero-dorsal 
part  is  only  slightly  curved. 

Ajfiidtiea. — A  species  from  (lie  .i-'enonian  was  figured  and  described  by  Goldfuss 


INOCERAMUS.  277 

as  7.  fJrippxi,  Mantel],  and  tliat  idnitification  lins  l)oen  accepted  by  many  later 
writers.  The  type  of  I.  Crippsi  came  from  the  Chalk  Marl  (zone  of  Schhimharhia 
varians).  From  a  study  of  a  cast  of  the  type,  Petrascheck  and  J.  Bohm^  came 
to  the  conclusion  that  the  Senonian  species  is  quite  distinct  from  /.  Crippsi,  and 
Bohm  has  named  the  former  7.  halHcus.  liohm  also  supports  the  view  first 
suggested  by  Messrs.  E.  T.  Newton  and  A.  J.  Jukes-Browne,  and  confirmed  by 


\ 


\ 


Fig.  35. — Inoceranms  Crippsi,  Mantell.     Upper  Greensaml,  Haldon.     Right  valve.     British  Museum  (Xat. 

Hist.),  No.  L17201.     Natural  size. 

Petrascheck,  that  7.  Jatiis  of  Goldfuss  and  of  d'Orbigny  (but  not  of  Mantel!)  is 
identical  with  7.  Crippxi,  IMantell.  After  a  careful  study  of  the  type  and  other 
similar  sj)ecimens  of  7.  Crippsi,  and  of  si)eciiiiens  of  7.  latnx,  I  can  fully  support 
these  conclusions. 

7.  cinicifonnis,  d'Orbigny,'  is  allictl  to   7.   Cvipp.^i,  hui.  is  relatively  higher.    One 
specimen  found  in  the   Up})er   Greensand  of  Warminster  (Plate  XLV II I,  fig.  ■^), 

1  '  Subhercyn.  KreitKinul.lc  ■  (1909),  pj..  41—4(3;  PitiasiLeik,  "luoceram.  a.  d.  Gosau."  •  Jahib. 
(1.  k.  k.  geol.  Rcichsanst.,'  vol.  hi  (1906),  p.  155. 

-  '  Pal.  Franc.  IVrr.  Cii't.,'  vol.  iii  (184C),  p.  512,  pi.  cccevii. 

37 


278  CRETACEOUS   LAMELLIBRANCHIA. 

sliows  some  reseinlilance  to  I.  cHnciformis,  but  is  probably  only  a  rather  liigli  form 
of  /.  Crippi^i,  with  which  species  it  is  found  associated. 

/.  orhicnlarif,  Goldfuss/  is  regarded  Ijy  Bohm  as  a  small  form  of  /.  Crippsi, 
Mantell. 

TiJ2)e. — In  the  British  Museum  (fig.  So)  from  the  Chalk  Marl  (zone  of  ScJilwu- 
hachia  variant)  of  Off  ham. 

DistrihiiJion. — Upper  Greensand  of  Haldon.  Upper  Greensand  (zone  of  Pecten 
aspcr)  of  "Warminster  and  Devizes.  Chalk  Marl  (zone  of  SrJila'iihacltla  rarian.i)  of 
Ringmer,  Hamsey,  Oti'ham,  Maiden  Newton,  Eggardon  Hill,  Tyrton,  Chalton, 
Arlesey,  Hunstanton,  and  Donnington  (Lincolnshire).  Cenomanian  of  Wilmington 
(Devon).  Lower  Chalk  (zone  of  Hohtster  suh(jlobosnii)  of  Totteruhoe,  Burham,  and 
Cherry  llintun. 

Inoceramus  CiMiM'si  nir.  iiKACiiENSis,  Ethoridjc,   188L      Plate  XLVIII,  figs.  4,  b  ; 

Plate  XLIX,  fig.  1. 

1881.  Inoceramus  IiKtus  \\\r.  rexchessis,  B.  Etheridje.  In  Peuuing  and  Jukes- 
Browne,  Geol.  Cam- 
bridge, p.  142,  i>\.  i, 
fig.  3. 

lie  marks. — In  this  form,  which  is  mainly  characteristic  of  the  zone  of  Ilolaxter 
anhijluhosus,  the  ribs  are  more  sharply  defined,  their  ventral  curvature  is  greater, 
and  their  posterior  part  is  less  nearly  straight  than  in  I.  CvippsL 

Tijpe. — From  tlie  Totternhoe  Stone  of  Burwell,  in  the  Sedgwick  Museum, 
Caml)ridge. 

Didrlhnt'wn.—  ChiAk  Marl  of  Blue  Bell  Hill,  Burham.  Zone  of  Ualastrr  snli- 
f/lohusiis  of  Merstham  and  Blue  Bell  Hill,  Burham.  Totternhoe  Stone  (zone  of 
II.  .snhijJdho.^iis)  of  Burwell.  Recorded  by  Etheridge  from  the  C-halk  Marl  of 
Reach. 

IiNouKKAMus  Etiikimdcki,  iiuiii.  inic.     Plate  XLIX,  figs.  2—4. 

1881.     Inockramus  convexus,  ii.  A'tlicrltlijc.     In    reniiing    and    Jukes-Browue, 

Gi'ol.    Cambridge,   [>.   lio,   pi.  ii, 
fig.  6. 

—  —  —         var.  QUADRATUS,  Etlieridije.     Ibid.,  p.    1-13,    pi.   ii, 

fig.  7. 

—  —  STRiA'ivs  wir.  cunvEXVs,  A.  J.  JiiJies-llroirne.   Cret.  Rocks  of 

Briiaiu,  vol.  iii,  p.  476. 

1  '  Polref.  Gerin.,'  vol.  ii  (1836),  p.  117,  pi.  fxiii,  fi^'.  2.  Biihm, '  Subhercyu.  Kreidemulde'  (1900), 
p.  Iti,  pi.  xi,  fig.  1. 


INOCEKAMUS.  279 

Nou  18S5.     Inoceramus  convexur,  J.  JArZ/and  F. /?.  J/eei-.  Foss.  Cret.  Nebraska  (Mom. 

Amer.  Acad.  Arts  and  Sci  , 
vol.  v),  p.  386,  pi.  ii,  fig  2. 

Description. — Valves  nearly  oqiial,  considerably  iiierniilateral,  tiimirl,  compressed 
near  the  postero-dorsal  mai'g'in  ;  lieit^lit  greater  than  length.  Antero-dorsal  margin 
nearly  straight;  ventral  margin  usually  very  convex  ;  posterior  margin  slifhtlv 
or  moderately  convex,  forming  an  ohtnse  angle  with  the  hinge-line.  Anterior 
marginal  parts  more  or  less  nearly  perpendicular  to  tlie  plane  of  the  valves,  some- 
times concave  near  the  nmho.  Uinbones  terminal,  curved  inwards  and  forwards. 
Angle  between  the  hinge-line  and  the  anterior  margin  is  about  115°.  The  hei'dit 
of  the  shell  is  nearly  twice  the  length  of  the  hinge. 

Ornamentation  consists  of  faintly  marked  concentric  undulations  and  numerous 
growth-lines. 

Affinities. — In  this  species  the  antero-dorsal  margin  is  relatively  longer  and 
more  nearly  straight,  and  the  postero-dorsal  ])art  of  the  shell  less  compressed  thnn 
in  J.  tenim,  Mantell. 

J.  conve<i-nii  var.  fpuidratus,  Etheridge,  "was  founded  on  a  specime]i  in  which  the 
antei'ior  part  of  the  shell  is  pressed  in,  giving  rise  to  the  appearance  of  a  carina 
at  the  upper  margin  of  the  antero-dorsal  slope. 

Types. — From  the  Totternhoe  Stone  of  Burwell,  in  the  Sedgwick  Museum, 
Cambridge. 

Distnlivfion. — Upper    Greensand    (zone     of    I'erten     a.^per)    of    "Warminster. 
Cenomanian    of  Wilmington,    Devon.     Chalk  Marl  of    Branscond)e,  Beer   Head, 
Titherleigh  (near  Chan!)  and  Hunstanton.     Totternhoe  Stone  (zone  of  Holastn-  ' 
siihgluhosii.'i)  of  Burwell. 


Inockpamis  I'lrrrs,  Soverhij,  ^ 829.     Plate  XLIX,  figs.  5,  0.     Text-fig.  30. 

1829.     JyocERAiivs  vic'ivs,  J.  de  C.  Soverly.     Min.  Conch.,  vol.  vi,  p.  215,  pi.  dciv, 

fig.  1. 
1854.  —  picTus,  J.  Morris.     Cut.  Brit.  Foss.,  ed.  2,  p.  170. 

1867.  —  ANGULATUS,  E.  Gvrraiiger.     Album  Pali'out.  de  la  Sartbi',  p. 

20,  pi.  XX  V,  fig.  7  (?  I.  ANQULATUS, 

trOiblyni,.  18-16). 
J904.  —  picTvs, E. T. Kill  h, II  \uu\  A.J. Ji(J.-iif-Bioiriie.  In  Jukfs-Browue, 

Cret.  Kocks  of  Britaiu,  vol. 
iii.  p.  150. 

Jhscrij'tloii.—iihdl  equivalve,  very  inequihiteial,  slightly  or  moderately  convex 
with  flattened  sides;  the  postero-dorsal  part  compressed.     Antero-dorsal  marginal 


280 


CRETACEOUS   LAMELLIBRANCHIA. 


part  flattened  or  concave,  and  more  or  less  neai-lj  perpendicular  to  the  plane  of 
the  valves.  Ventral  margin  very  convex ;  posterior  margin  moderately  convex. 
Umbones  terminal,  incurved.  Hinge-line  nearly  at  right  angles  to  the  anterior 
margin.  Ornamentation  consists  of  nunierons  strong,  somewhat  irregular  concen- 
tric ribs,  separated  l)y  concave  interspaces.  Tlie  curvatui-e  of  the  ril)s  is 
unsyrametrical,  and  the  ribs  become  less  distinct  on  the  antero-dorsal  and  postero- 
dorsal  parts  of  the  valves. 

Affinities. — This  species  shows  some  i-esemblance  to  I.  amjlit-us,  but   possesses 
moi'e  numerous  ribs,  and  also  differs  in  the  anterior  part  of  the  shell  being  flat  or 


Fio.  3(). — Inoreramus  juXiis,  Sow.     Clialk  Marl,  (iuiklfoid.     liritish  Musmim  No.  4'.i'21'2.     Tlic  Typo. 

Natural  size. 


concave.  The  tyi)e  and  some  other  specimens  (e.  tj.  No.  73339,  British  Museum) 
show  traces  of  the  original  colouring  of  the  shell.  An  example  of  this  sjjecies 
was  figured  by  Gueranger  as  /.  ancjulatus,  d'Orbigny,'  but  appears  to  be  quite 
distinct  fi'oin  that  form. 

Type. — From  the  Cluilk  Marl  of  Guildford,  in  the  British  Museum  (Natural 
History). 

Dixfrihiifion. — LoAver  Clialk  (zone  of  JTohtstor  siibriJuhosHs)  of  Beachy  Head, 
Burham,  Kochester,  and  the  Cog-ina-gogs,  near  Cambridge.  Chalk  Marl  of 
Burham  and  Guildford. 

'  '  Pal.  Fiau^.  Terr.  Crct.,'  vol.  iii  (1816),  j).  ill.S,  \A.  ccccviii,  figs.  3,  -i.  lu  the  text  the  spelliug 
is  ancjulosus. 


INOCERAMUS.  281 


Inocruamis  i,\r;iATUs  (l^chlnlheiiii),  ISl:'..      Plato  ],.     Text-fio-.  37. 

1768.      OsTRAClTES,  J.    K.    I.    Waleh.       Dir    Niiturgeseh.    Vcrstciil    z.    Erlilul.     d. 

Knorrischeu  Saiiiiul.  v.  Mcrkwiinlij^'k.  d. 

Natur.,    II,  p.   8-t,   pi.    B    11/;*,   fi^'.   2; 

p.  152,  pi.  dx,  figs.  1,  2. 
1813.  —  LABiATus,  E.  F.  V.  Schlotheim.     lu  LeonliarJ's  Taschcubuch 

fiir  Mill.,  vol.  vii,  ]>.  93. 

PiNNITES    DILUVIANUS,  Sell hltliri III .        IllilL,  p.  U'-j. 

1820.  —  —  SchlotL'iiii.     Potrefactenk.,  p.  303. 

1822.     Mttiloides  labiatus,  A.  Bi-ainjiiiitrt.    Tu  Cuvier,  Ossomcus  Fossil  s,  vol.  ii, 

pt.  2,  j.p.  320,  .597,  pi.  iii,  fig.  4. 

1822.  Inoceramus  mytilloides,  (t.  Manti-ll.      Foss.  S.  Downs,  p.  215,  pi.  xxvii, 

fit;.  3  ;  pi.  xxviii,  fig.  2. 

1823.  —  MYTii.oiDEs,  /.  dc  U.  tiowerhij.     Miu.  Couch.,  vol.  y,  p.  62, 

pi.  ccccxlii  (not  the  two 
smaller  figuies). 
1827.     Catilltjm  Schlotheimi,  S.  NiUson.     Petrlf.  Sueuaua,  p.  19. 
1836.     Inoceramus  mytiloides,  A.   Gohl/uss.     Petref.  Germ.,  vol.  ii,  p.  lis,  pi. 

cxiii,  fig.  4. 
?  1837.     Catillus  mytiloides,  G.  G.  Pusch.     Polens  Paliiout.,  p.  45. 
1841.     Inoceramus  mytiloides,  F.  A.  Rimer.     Die  Versteiu.   il.    uorJ-deutscli. 

Kreidegeb.,  p.  63. 
1846.  —  pkoblematicus,  A.  d'Orbiyny.     Pal.  Fraii^.  Terr.  Crct.,  vol. 

iii,  jj.  510,  pi,  ccccvi,  figs. 
1 — 7  {Non.  I.  jirohlemalicun, 
V.  Schlotheim). 
— .  —  mytiloides,  a.  E.  Reiiss.     Die  Verstein.  der  biihrn.  Kreide- 

format  ,  pt.  2,  p.  26,  pi.  xxxvii, 
fig.  16. 

—  —  —  H.  B.  Guinity..     Griuulr.  d.  Versteiu.,  p.  463. 
!'1847.              —                    —            A.  d'Archiac.     Mem.  Soe.  gi'ol.  de  France,  ser.  2, 

vol.  ii,  p.  307. 
1850.  —  peoblematicus,  A.  d'Orbigny.     Prodr.  de  Pal.,  vol.  ii,  p.  197. 

—  —  mytiloides,  H.  B.  GeiiiUz.     Das  Quadersaiidst.  oder  Kreide- 

geb. in  Deutschlaud,  p.  176. 
'i  1852.  —  —  F.  BiJmer.     Kreidebild.   v.  Texas,  p.  60,  jil.  vii, 

fig.  5. 
1854.  —  —  J.  Mfirrin.     Cat.  Brit.  Foss.,  ed.  2,  p.  170  (jOTr/iwi). 

1863.  —  —  A.    v.    Strombeck.      Zeitschr.    <1.    deiitseh.    geol. 

Gesellsch.,  vol.  xv,  p.  119. 

p  1870.  latus,   F.  liiimci:     Geo!,    v.    ()l>erschles.,    p.    316,    pi.    xxxiv, 

fig.  12. 
1871.  _  LABiAius,  F.  ,Sf„llc:kii.      Paluiout.    ludiea,  Cret.    Fauna    S. 

ludia,   vol.    iii.   p.   40H.   pi.    xxix. 
Ck.  1. 


282  CRETACEOUS    LAiyiELLIRRANCHIA. 

1872.  iNOCEEAMrs  LAiiiATUS,  H.  B.  Geinitz.     Das  Ell)thalt|;fb.  in  Saelisen  (Pal- 

oeontoijrapliica,   vol.   xx,  pt.   2), 
p.  46,  1)1.  xii,  fi;,'8.  1 — 3. 

1873.  —  —  Geinitz.     Neiies  Jalirb.  fiir  Mill  ,  etc.,  p.  13. 
1877.              —                  —  C.  SchllHer.     Pala-outographica,  vol.  xxiv,  p.  2(;2. 

—  • —  —  A.  Fritsch.     Slucl.  ini  Grt-bieto  der  Ijiilmi.    Krcide- 

forniat.  ii,  Weisspiibcr^'.  \\.  Malnitz. 
Sc'hicht.,  p.  130,  fig.  112. 
^  1888.  —  —  -S'.   Nilitiii.      Les   Vestiges  Cn't.    Euss.    eentrale 

(Mum.  Coniite  gt'ol.  Euss.,  vol.  v, 
no.  2),  p.  34,  pi.  5,  figs.  10,  11. 
1888.  —  —A.  Peron.      Hist.  Terr,  de  Craie  daus  le  S.E.  du 

Bassiu  Anglo-Parisien,  p.  158. 
1893.  —  —         F.  Mirlinel.     Zeitsclir.  der  deutsch.  geol.  Gesellsch., 

vol.  xlv,  p.  241. 

—  —  -  T.  W.   Stn)iton.      The   Colorado    Fonnatiou    (Bull. 

U.S.  Geol.  Surv.,  No.  106),  p. 
77,  pi.  X,  fig.  4  ;  pi.  xiv,  fig.  2. 
?  1897.  —  —It.  Leonluinl.     Kreideforiuat.  iu  Ober.schles.  (Pal- 

fBoutograpbica,  vol.  xliv),  p.  48. 
1903.  —  —  TI^.  Pftrasfhvcl:     Jalirb.  d.  k.  k.  geol.  Eeich.^au.st., 

vol.  liii,  p.  1,'J6. 

?  Nou  18C8.  -  MYTihoiDES,  E.  Ficliwuld.     Letlia?a  Eossiea.  vol   ii,  p.  492,  pi. 

xxi,  fig.  6. 
-—   1881.  —  (Mttilites)  rROBLEMATicus,  R.  Etheridije.     In  Penning  and 

Jukes-Browne,  Geol.  Cambridge, 
p.  143,  pi.  iii,  figs.  9— 11. 

De.'tcripfinn. — Shell  inytiliform,  nearly  cquivalve,  extremely  inequilateral, 
oblique,  much  elongated  between  the  umbo  and  the  postero-ventral  extremity, 
convex,  with  a  small  posterior  ear ;  aiitero-dorsal  part  sloping  steeply  and  some- 
times concave.  Angle  formed  by  the  hinge  with  the  antero-dorsal  margin  about 
90°.  Umbones  terminal,  with  a  slight  antei'ior  curvature.  Anterior  margin  gently 
curved;  postero-ventral  extremity  very  convex;  posterior  margin  nearly  straight. 

Ornamentation  consists  of  small,  fairly  regular  concentric  undulations,  which 
have  an  unsymmetrical  curvature  in  the  young,  but  become  more  nearly  symmetrical 
in  older  specimens.  On  the  old  i)arts  of  the  shell  the  undulations  become  less 
distinct. 

AflinificK. — It  seems  probable  that  this  species  is  related  to  /.  Crijijisi  var. 
rcachensis  (p.  278),  but  the  height  of  the  shell  is  relatively  greater,  the  length  of 
the  hinge-line  is  less,  and  the  direction  of  growth  is  oblique  to  the  hinge-line. 

/.  pwpiiupius,  Goldfuss,' from  the  Quader-sandstone  of  Schandau,  Avns  regai'ded 
by  Geinitz  as  a  sj'nonym  of  I.  lahidiii.'i. 

1  '  Petref.  Germ.,'  vol.  ii  (1836)  p.  112,  jil.  cix,  fig.  H. 


mOCERAMUS. 


283 


D'Orbigny  identified  this  species  with  /.  prohlematicits,  von  Schlotheini,  which 
comes  from  the  Senoniai:,  and  has  been  shown  by  Bolim  to  be  distinct  from  the 
Tiu'onian  form.^ 

lieniarks. — This  species  is  mainly  characteristic  of  the  zone  of  lih[/nch<jiicUa 
Cavieri.  In  the  zone  of  Terehratuliua  lata  it  is  not  common,  and  the  shell  is 
nsually  relatively  longer  than  in  typical  forms  of  the  species. 

TijiK-s. — The  type  came  from  the  Turonian  of  I'irna.  The  sjiecimens  figured  by 
Man  tell  from  the  zone  of  Blujuclionella  Cavieri  of  Pliimpton  are  in  the  British 
]\fnseum.  The  large  specimen  figm-od  by  Sowerl)y  fi'om  AVarminster  cannot  1k> 
found. 

Diiitribiitlon. — Zone  of  Bh//urJtoncll(t  Cavieri  of  the  Devon  and  Dorset  coasts,  the 
Isle  of  Wight,  AVinchester,  Eastbourne,  Lewes,  Plumpton,  Dover,  Blue  Bell  Hill 
(Burham),  Betchworth,  Watlington  (Berkshire),  Hitchin,  Cherrj'  llinton.  South 
Thoresl)y,  South  Ferriby  (Lincolnshire),  antl  the  Yorkshire  coast.  Zone  of 
Tcrehratnlhiii  lain  of  the  Devon  and  Dorset  coasts,  Winchester,  Eastl)ourne,  and 
Dover. 

Recorded  by  Jukes-Browne  from  the  zone  of  Holaster  sub(jlohosas  of  Cambridge- 

FiG.  37. 


Fio.  38. 


•i^-. 


:^ 


Via.  til.—Inoceramus  laiialus  (Schloth).      Tlio  typo  of  Inoceramus  mylilnides,  MautfU,  '  Foas.  S.  Downs,' 
p.  215,  pi.  xxviii,  fig.  2.     Zone  of  K/nyiic/ioiicHu  t'lii-icrt.  Plumpton.     Ui-itish  Miisfum.     Nntunil  size. 


ipton 
Fio.  38. — Inoceramus  labia/us  vjir.  hihis,  Sow.     Zoiio  of  lli>hisf,i- iilnnns,  ruik-y  Junctioa  Station. 

Musuuni,  No.  L211'J1.     Natiu-.il  sizf. 

1  J.  Bolini,  '  Moiiatsber.  d.  d.;utsch.  gwl.  Gesellsch.'  (ll}Oi>),  p.  117. 


British 


I 

I 


284 


CRETACEOUS   LAMELLIBRANCHIA. 


sliire  and  West  Norfolk  ;  ami  1)y  Rowe  from  the  zone  of  Holaster  j;/«j(»s  of  Dover 
and  tlic  Sussex  coast,  and  from  the  zone  of  Mirraslev  cor-tc.stndinnrium  of  Dover. 


Fiu.  39. 


Fk!.  40. 


Fig.  3"J. — hioceramus  labiatus  var  latus,  Sow.       Zone  of  Hohister  p/miiis,    Swafl'ham,  Norfolk.      Nonvich 

Museum,  No.  329(5.     Eight  valve  and  anterior  view.     Natural  size. 

Fig.  40. — Inoceramvs  labiatus  var.  Intvs.  Sow.      One  of  tlie  types  of  Iiwceramvs  latus,  Sowerljy,  'Min.  Conch.,' 

vol.  vi,  \i.  I"i9,  pi.  ill.\.xxii,  fig.  1  (lower  figure).     Swaffliam.     British  Museum,  No.  43266.     Natural  size. 


Inoc'ER.uiiis  i,.\ hiatus  var.  i,atus,  SuirerJi;/,  1828.     Text-figs.  38 — 40. 

1828.     Inoceramus  latus,  /.  du  C.  Soirerhij.     Miu.  Couch.,  vol.   vi,  p.   15ft,  [,]. 

dlxxxii,  fig.  1.  (Noil  /.  hili/s, 
Mantell). 

1854.  —  —J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  170  itnuilni)- 


TiriiKirls. — Tliis  variety  differs  from  /.  luhinhi^  in  the  much  greater  length  of 
the  hinge-line  in  proportion  to  the  height  of  the  shell,  in  the  greater  convexity  of 
the  anterior  margin,  the  smaller  convexity  of  the  ventral  margin,  and  the  less 
oblique  form  of  the  shell.  On  account  of  the  greater  length  of  the  hinge-line  the 
curvature  of  the  ribs  and  growth-lines  is  broader  than  in  /.  luhidtns. 

This  vai'iety  appears  to  be  confined  to  the  zone  of  Ilolastev  plaitit.'t,  and  is 
common  in  the  neighbourliood  of  Swaffham,  Norfolk.  The  larger  specimens  which 
I  have  seen  are  not  sufficiently  jierfect  for  figuring,  but  a  characteristic  exam^jle 
is  figured  by  Sowerliy. 

Types. — From  the  zone  of  IJoIa.^fer  planus  of  Swaffliam.  The  smaller  specimen 
figured  by  Sowerl)y  is  in  the  British  IMuseum  (Fig.  40),  but  the  larger  specimen 
cannot  be  found. 

Distrilmfion. — Zone  of  Ilolaster iilaniis  of  Purley  Junction  Station,  Surrey,  and 
SwalTham,  Norfolk. 


Ipalaeontoovapbical  Society,  \o\\ 


A    MONOGRAPH 


CRETACEOUS    LAMELLIBRANCHIA 


OP 


ENGLAND. 


BY 


HENRY  WOODS,  M.A. 

UNIVERSITY   LECTURER   IN    PAL^OZOOLOOT,   CAMBRIDOE. 


VOL.  II.     PART  VIII. 
INOCERAMUS  {continued). 
Pages  285— S-iO;   Plates  LI— LIV. 


LONDON: 
PRINTED     FOR     THE     PAL^ONTOGRAPHIC  AL    SOCIETY. 

1912. 


PRINTED  BY  ABLARD  AND  SON,  LONDON  AND  DORKING. 


INOCERAMUS.  285 


Fio.  41. — Inoceramus  lahialus  viii\  latiis.  Sow.     Zone  of  Holaster  2>l''>i>is,  Coombe  Bissett.     Dr.  Blackniore's 

Collection.     Right  valve.     Natural  size. 

Inoceramus  inconst.vn.s,  sp.  nov.     Plate  LI,  figs.  1 — 4.     Text-figs.  39,  42 — 49. 

1822.     Inoceramus  Brongniarti,  var.,  G.  ManteU.     Foss.  S.  Dowus,  p.  215,  pi. 

xxviii,  fig.  3. 
—  —  SP.  Maniell.      Ibid.,  p.  217,  pi.  \xvii,  fig.  9. 

1850.  —  Lamarckii,  J.  de  C.  Sowerlij  in  F.  Dixon.     Geol.    Sussex,    p. 

355  (p.  385,  ed.  2), 
pi.  xxviii,  fig.  29. 
1904.  —  Brongniartii,  C.  Airajhi.    Boll.  Soc.  geol.  Italiana,  vol.  xxiii, 

p.  192,  pi.  iv,  figs.  3—5. 

Description. — Shell  extremely  inequilateral,  moderately  or  slightly  inequivalve; 
the  early  part  of  the  shell  slightly  convex  or  nearl\'  flat,  the  later  part  much  more' 
convex  and  sometimes  growing  nearly  perpendicularly  to  or  forming  a  large  angle 
with  the  early  part,  so  that  in  old  individuals  the  shell  liecomes  more  inflated  ;  in 
other  cases  the  convexity  increases  more  gradually  from  tlie  earlier  to  the  later 
stages  of  growth  and  a  nearly  glolxise  shell  results.  Height  of  the  shell  often 
rather  greater  than  the  length.  Hinge-line  long,  forming  rather  more  than  a 
right  angle  with  the  anterior  margin,  which  is  usually  more  or  less  nearly  straight. 
Ventral  and  posterior  margins  rounded.  Umbones  terminal,  small,  jjointed,  only 
slightly  curved.  Anterior  marginal  part  of  the  valve  usually  flattened,  but  not 
definitely  limited  from  the  sides  of  the  shell.  Posterior  ear  developed  but  not 
distinctly  limited. 

Concentric  folds  are  usually  well  developed,  l)ut  ])cc()me  indistinct  on  the 
anterior  flattened  area,  on  the  posterior  ear,  and  on  the  later  part  of  the  valve 
of  old  individuals.     The  concentric  folds  have  a  very  unsymmetrical  curvature. 

Remm-hs. — The  forms  iuehuled  in  this  species  vary  consideral)ly,  owing  mainly 
to  the  length  of  duration  of  the  flattened  stage,  which  in  some  individuals  forms  a 

38 


286 


CRETACEOUS    LAMELTJURAXCII  lA. 


small  part  (Figs.  4:5,  48,  4'.»)  l)ut  in  others  a  large  part  (Plate  LI,  fig.  2,  Text-figs. 
45,  4(5)  of  the  eiitii'(>  shell.'  Also  the  passage  IVom  one  stage  to  tlie  other  is 
sometimes  gradual,  so  that  the  section  ol"  the  shell  t\)i'nis  a  fairly  miiform  eui-ve 
(Fig.  48),  but  generally  tlie  change  is  abrupt,  so  that  the  later  part  of  the  valve  is 


Fifi.  42. — Inocei-amus  imuustans,  sp.  iiov.  The  orisjinal  of  I iioceramus  sp..  Manti-ll,  '  Foss.  S.  Downs,'  p.  217, 
pi.  xxvii,  h'r.  y.  Ujjpor  Chalk,  Lowes.  Britisli  Musoum,  No.  -ilO-').  Left  valve  and  posterior  view. 
Natural  size. 


>_>*'' 


Fia.  43. — Inoceramus  incoHslttns,  sp.  nov.     Zone  of  Holaster  planus,  Swall'hain,  Norfolk.     Norwirli  Museum. 
Left  valve,  and  posterior  and  dorsal  views  of  the  same.     Natural  size. 

bent  at  an  angle  with  the  earlier  part  (Figs,    l-^,    I-!).     The  length  of  the  hinge-line 
in  proportion  to  the  height  ot"  the  shell  shows  some  variation  and  conse(piently  the 

'  Tlio  larger  spcciiucu  of  I.  hifii:i,  Sowcfliy    ('  Mill.  Coueli.,'    vul.    vi,   pi.  dlxxxii.  ujjper  figure), 
■which  eanuot  uuw  be  foiuid,  is  ja-oliulilv  an  example  of  this. 


Fi<;.   I.-. 


Fig.  44. 


Fio.  4ri.—Inoce)-amus  inconshins,  sp.  nov.  The  oiiifinal  of  /.  llmitjuiarli,  var.,  MaiitcII,  '  Foss.  S.  D.iwns," 
p.  215,  pi.  x.xviii,  fijj.  3.  Upper  Clialk  (prol)al)Iy  zone  of  Mirraster  cur-aifiiiinum),  Soutlieraui.  British 
Musevim,  No.  5878.     Right  valve.     Natural  size. 

FiQ.  4r,.—Inoceramus  mconsfaiis,  sp.  nov.     Upper  Chalk,  Sil-sslx.     liritish  Jliiseum,  No.  5861).     Left  valve 

and  anterior  view.     Natural  size. 


Fio.  -Mi. — />i  Off  rum  lis  I'neonii'nii.'i,  sp.  nov.     Zone  of  Hiihtnler  j'/niiii.i,  SnafTliani,  Norfolk.     Norwioh  Miitioum. 

Right  valve.     Natural  size. 


288 


CRETACEOUS   LAMELLIBRANCHIA. 


curvature  of  tlio  I'ibs  varies.  In  some  specimens  (often  of  large  size)  the  shell 
is  thinner  tlian  usual  and  has  sharp  and  ridge-like  folds  similar  to  those  of 
7.  Lamarcld  var.  Wi-bsteri,  Mant.  (p.  818).  Further  work  may  show  that  it  is 
desirable  to  eive  names  to  some  of  the  varieties  of  I.  inconstans. 

Affinities. — This  species  is  closely  allied  to  /.  hihiatns  var.  lafus,  Sowerby;' 
but  the  hinge  is  relatively  longer  and  the  height  of  the  shell  less,  the  anterior 
flattened  area  is  larger,  the  later  part  of  the  shell  is  more  convex,  the  umbones 
ai'e  less  jirominent  and  the  posterior  ear  more  distinct. 


.#■.-.-•  \Vi9'.^3r  ■  mr-.—Ja 


Fig.   -t". — Inocevamus   iticnnstans,   sp.   nov.       Upper  Chalk    (zone  of   Actinocamax   quadratiis),    liii|^')iton. 
Brighton  Museum,  No.  336.     Right  valve  and  anterior  view.     Natural  size. 

7.  incon,<itan>i  is  distinguished  from  1  .Lamarclci,  Parkinson  (p.  807),  by  the 
relatively  longer  hinge-line,  the  more  unsymmetrical  curvature  of  the  folds,  the 
flattened  form  of  the  early  part  of  the  shell,  the  less  prominent  umbones,  and 
tlie  smaller  difference  in  the  size  of  the  valves.  1.  Guvien  of  Andert"  appears  to 
l)e  a  flat  form  of  /.  inconstans.  Another  specimen  figured  by  Andert''  is  allied  to 
7.  ineonstivutt,  but  its  a.xis  of  growth  is  more  ol)lique  and  its  hinge  longer  than  usual. 

1  Erratum  ou  p.  ^84  (fig.  39)  :  for  Tvoceramvn  Jahiatus  var.  latug.  Sow.,  read  Inoceramns  incon- 
stayis,  sp.  uov.  A  specimen  figured  by  Audert  (' Inocerameu  d.  Kreiltitz-Zitfavier  Sandsteingeb.,' 1911, 
]).  45,  pi.  i,  fig.  5)  as  I.  Cuvieri  var.  planus  appears  to  be  iuterinediate  between  I.  lahuitita  aud/.  labiatus 
var.  latus. 

~  Loc.  cit.,  pi.  ii,  fig.  2. 

'  Loc.  cit.,  pi.  i,  fig.  2,  pi.  vii,  fig.  8  (/.  Cuvieri  var.  ^'/("(".s). 


INOCERAMUS. 


289 


"^^S^i^^ 


Fiu.  -IS. — Inoceram'is  iHcoiisdiHS,  sp.  iiov.     Upper  Chalk.     Ijowility  unknown,     lliitisli  MiisiMiiii,  No.  3<WS2. 

lA'ft  valve  and  dorsal  view,      x  \. 


2;  10 


CRKTACEOUS    LAM  i:i.I>IHRANCHIA. 


J 


Fig   49— Inoccra»ms  iHf..«s/..ii.s-.  sp.  nov.     Zone  of  Adinocomax  qnml mtus.  East  HiirnlKim,  Salisbury.     Hr. 
Blackmoro's  CollLc4ion.     Left  valve  and  dorsal  view.     Natural  size. 


IXOCERAMUS.  291 

T///ics.~  'V\\o  specinieii  Hgured  by  Aiaulull  as  /.  JlniiKjuiarfi  x-.w..  IVoin  tlu'  Upper 
Clmlk  (pnil)alily  zone  of  Micrastrr  cor-aiKjtiimim)  of  Soutliei'am  (l^cwes),  and  tlie 
one  Hiiurcd  as  Liof'ninin^i  sp.  l)y  tlu'  same  antlioi'  from  Lewes,  and  /.  Lt iu(trrl-'i, 
S()\vt>i-l)y  (in  Dixon),  fVoni  tlie  Chalk,  Snssex  (prolmbly  zone  of  Trirhrnlnliud. 
lif'i  of  ]\[allino-"),  ai'e  in  tlic  British  ]\fus(Mim.  Xos. -5878,  I7l>'>,  li'Jolt-V)  I'csncct  ivclv. 


Fig.  oO — /«o<cioi)i»s  iiicoMs/oiis, sp, nov.  var.     Sriioiiian.  Haldon.     Uritish  Museum, Xo.  LlTySO.     Left  valve. 
A  large  flat  form  resembliug  /.  cijdoides,  Wegner.     Compare  with  Fig.  4(i.      x  J. 

Distribution. — Zone  of  Ifiiln-sfc)-  iihiiias  of  Twyford,  Swaffliam  (Xorfolk),  anil 
Strood.  Zone  (if  Mirvustur  cor-ti'ntiiiHintriinii.  of  C'lintliam,  Guilford  Colliery 
(Coldivd  near  Dover),  and  AVlianam  (^'orkshire).  Zone  of  Micraster  cor-an<jniiiiuii 
of  Soutlieram  (Fiewes).  Zone  of  Acfiiioc((m((,i:  rjuadratits  of  East  Harnliaiu 
(Salisbury)  and  lirighton.  Zone  of  Bcleinuitdla  vincronata  of  Siiiile  (Isle  of 
\Vight).     Probaljly  also  in  the  zone  of  Terebnitalina  lata. 


292  CRETACEOUS   LAMELLIBRANCHIA. 


Inoceeamus  inconstans  frtr.  stkiatis,  Mmtti'Il,  1822.     Plate  LI,  fig.  o ;  Plate  Lll, 

1822.     Inoceeamus  strixtvs,  G.  Mantell.     Foss.  S.  Downs,  p.  217,  pi.  xxvii,  fig.  5. 
1828.  —  —       J.  de  C.  Sotverby.     Min.  Condi.,  vol.  vi,  p.  160,  pi. 

dlxxxii,  fig.  2. 
1854.  —  —       J.  Morrii<.     Cat.  Brit.  Foss.,  ed.  2,  p.  170  (jwW/m)- 


Nou  1836.  —  —        A.  GoZ(//'».s8.     Petref.  Grerm  ,  vol.  ii.  p.  ll-l.  pi.  c.\ii. 

tig.  2. 

—  1841.  —  —       F.  A.  Itiimer.     Die      Verstein.      cl.      uord-dentsdi. 

Kreidegeb  ,  p.  62 

—  184C.  —  —        A.  E.  Reasg.     Die  Versteiu.  der  boluu.  Kreidi'lor- 

mat.,  pt.  2,  p.  25. 

—  1846.  —  —        A.  (rOMijnij.     Pal.   Frauc.  Terr.   Cret.,  vd.   iii,  p. 

508,  pi.  ccfcv. 

—  1850.  —  —        d'Orbigiiy.     Prodr.  de  Pal  ,  vol.  ii,  p.  168. 

—  1852.  —  —       F.  Romer.     Kreidebild.  v.  Texas,  p.  60. 

—  1868.  —  —        A.  V.  Strombecl-.     Zeitsdir.  d.  deutscb.  geol.  Gesell- 

seli.,  vol  XV,  p.  108. 

—  1863.  —  —A.  Kunth.     Iliid.,  vol.  xv,  p.  727. 

—  1870.  —  —        F.  R'iiner.     Geol.  v.  Oberschlesieu,  p.  340,  pi.  xxix, 

fig.  6. 

—  1872-73.        —  —       H.  B.  Getnitz.     Das  Elbtbalgeb.  iu  Sadiseu   (Pal- 

aeontographica,  vol.  xx,  pt.  1), 
p.  210,  pi.  xlvi,  figs.  11—13;  (ibid., 
pt.  2),  p.  41,  pi.  xiii,  figs.  1,  2, 
It,  10. 

—  1873.  —  —        Geinitz.     Neues  Jalirl).  f  iir  Min.,  etc.,  p.  7. 

—  1877.  —  —        A.  Fritsch.     Stud,    ini  Gebiete   der  bijhm.   Kreide- 

forinat.  ii,  Weissenberg.  u.  Maluitz. 
Sdiidit.,  p.  120. 

—  1881.  —  —        J.  Kiesow.     Sclirift.  nat.  Gesellseh.  Dautzig,  vol.  v, 

p.  413. 

—  1885.  —  —       F.  NiitUiifj.     Die  Fauna  d.  baltisch.  Cenoman.  (Pal- 

aeont.  Abhandl.,  vol.  ii),  p.  23,  pi.  iii, 
figs.  11,  12. 

—  1893.  —  —        R.  Michatl.     Zeitschr.   d.  deutsch.  geol.  Gesellscb., 

vol.  xlv,  p.  233. 

—  1895.  —  —       E.  Tiessen.     Ibid.,  vol.  xlvii,  p.  480. 

—  1897.  —  —       H.Woods.     Quart.  Journ.  Geol.  Soc,  vol.  liii,  p.  381, 

pi.  xxvii,  fig.  13. 

—  1911.  —  —       A.  Fi-itsch.     Stud,  iin  Gebiete  biihrn.  Kreideformat. 

(Ergiinzuug   zu   Bd.   I,    Korycaner 
Schidit.),  p.  42,  fig.  190. 


INOCERAMUS.  293 

Uoimii-s. — This  variety,  wliicli  is  uncommon  and  of  small  size,  is  distinguished 
by  the  strongly  inflated  valves,  tlie  large  angle  between  the  hinge-line  and  the 
anterior  border,  tlie  absence  of  folds,  and  the  absence  or  indistinct  character  of 
the  anterior  flattened  area  and  of  tlie  posterior  ear. 

Tijpes. — The  type,  from  the  zone  of  Mlcnisfer  cor-inKjniitinn  of  Soutlierani, 
Lewes,  is  in  the  British  Museum,  No.  47G8  (Plate  LI,  fig.  5).  Tiie  specimen 
figured  by  Sowerby  from  the  Upper  Chalk  (probably  zone  of  Uolasfer  planus)  of 
Heytesbury  is  also  in  the  British  Museum,  No.  4o267. 

Distribution. — Zone  of  Holaster  2)la)ius  of  Stonelmll  siding  near  Dover,  and 
Swaffham,  Norfolk.  Zone  of  Micraster  cor-angninum  of  Southeram.  Upper 
Chalk  (probably  zone  of  Holaster  idanus),  Heytesliury. 


Jnoceijamls  ixcoxsTANs  (;((/'.  sAiJLMKXsis,  cur.  nor.     Plate  LIL  tio-s.  2,  o. 

A  variety  found  in  tlie  zone  of  Actinorama.r  (juiolratus  of  East  llarnham 
(Salisbury),  Mottisfont,  and  "West  Meon  (Hampshire),  is  distinguished  bv  tlie 
uml)ones  being  more  prominent  and  not  terminal,  by  tlie  regular  convexity  and 
equal  size  of  the  valves,  the  absence  of  tlie  anterior  flattened  area,  and  the  absence 
or  indistinct  character  of  the  concentric  folds.  This  variety  is  connected  with 
typical  forms  of  the  species  by  some  examples  (Fig.  49)  in  which  the  earh'  part  of 
the  shell  is  less  convex  and  possesses  di-stinct  folds,  but  the  nmbones  are  not  quite 
terminal  and  tlie  anterior  flattened  area  is  not  present.  J.  inconstans  var. 
narumensls  appears  to  resendile  T.  Brancoi,  "Wegner,"  of  which  good  figures  have 
not  yet  been  luiblished. 


Lnoceramds  liAi/ricus,  lidhm,  1907.     Text-figs.  -jI  —  ')■}. 

183(5.     Inoceramus  Cripsii,  A.  C^''</<(/'«^•(?.     Petref.  Gt-rm.,  vol.  ii,  \i.  116,  pi.  cxii, 

fig.  46.  (Nou  I.  Crippsi,  Mantell,  1822). 

1870.  —  —      var.  SULCATA,  i''.  i?.i;»f)-.     Geol.  v.  Oberschles.,  p.  35<). 

p!.  .\xxi.\,  fig.  9. 

1907.  —  BALTicus,  /.  Bi'ihm.     Zfitsclir.    il.    deutscli.    geol.    Gesellscli., 

vol.  lix,  Mouatsber.,  p.  113. 

1909.  —  —        /?.;/(<*(.     Sublu'ivvn.   Kroidfiiiul.le   (Alihan.ll.   .1.   k. 

]ir«.'Uss.  geol.  Laiulesaust ;   n.f.  5G),  p.  47, 
pi.  xi,  fig.  2a,  pi.  xii,  fig.  1<(. 

1910.  —  -        .1.  Noii-iih.      J{iill.    Intemat.    Acad.    Soi.    Cracovie 

(1909),  p.  875. 


'  '  Zt'itsclir.  d.  deutsch.  geol.  Gesellsch.,'  vol.  Ivii  (1905),  p.  159,  fig.  4. 

39 


294 


CRETACEOUS   LAMELLIBRANCHIA. 


Description. — Shell  equivalve,  ver}' inequilateral,  slightly  or  moderately  convex, 
becoming  ver\-  convex  in  old  specimens,  in  which  the  later  part  of  the  shell  grows 
either  perpendicularly  to  or  at  an   obtuse  angle  Avith  the  earlier  part ;  posterior 


'^^-^. 


Fio.  51. — Inoceramus  haltints,  Biiliiii      St'iioiiian,  Worbarrow  Bay,  Dorset.     British  Museum,  Nu.  L:;2177. 
J'lint  cast.     Ri"-lit  valve  ami  anterior  view.     Natural  size. 


Fia.  52. — Inoceramus  lalticus,  Bulim.     Anterior  view  of  specimen  shown  in  Fi<^.  53.      x  J. 

and  postero-dorsiil  pai'ts  compressed;  length  greater  than  height,  the  difference 
increasing  with  age.  Anterior  and  ventral  margins  rounded ;  posterior  margin 
forming  an  obtiise  angle  wath  the  hinge.  Hinge-line  long.  Umbones  rather 
small,  nearly  terminal. 


INOCERAMUS. 


295 


Concentric  ribs  strong,  sliarp,  narrow,  witli  a  very  unsymmetrical  curvature  ; 
a  few  ribs  may  come  off  from  the  sides  of  otlier  riljs;  between  tlio  ribs  are  broad 
concave  interspaces.     On  the  marginal  ])arts  of  okl  specimens  ribs  are  absent. 

Affinities. —  /.    hiillirns    is    closely    allied    to    f.    inronsfuns,    IVom    whic-li    it   lias 


'  ) 


X 


\ 


\ 


Via.  53.— /iiofei-aniiis  hiilticus,  Buhiii.     Upjx^r  Cliiilk  (proliiiWy  zone  of  Mannpiles  testudinarius),  Brighton. 
Mtisoiiiii  of  I'nioticiil  Oeology,  No.  2.).jO!».     I,i>ft  valve  .iiul  dorsjil  view,      x  }. 

probably  been  derived;  it  differs  from  that  species  by  its  longer  hinge  and  the 
longer  shell,  with  the  umbones  not  quite  termin;il.  The  length  of  duration  of  the 
slightly  convex  stage  varies  in  the  same  way  as  in  /.  incini.'itdii.t.  The  specimen  of 
/.  iiu-oiisftin.'i  .shown  in  Fig.  40  makes,  on  account  of  its  longer  hinge,  some 
approach  to  /.  balticus.^ 

'  See  also  Bubiii,  loo.  cit.,  pi.  xii,  fig.  Id. 


20(5  CRETACEOUS   LAMELLIBRANCHIA. 

J.  reijuhirix,  irUrljignj','  differs  from  J.  hdlticns  in  the  outline  of  the  t^liell,  in  its 
uniform  convexity,  and  in  tlie  broader  and  less  sliarp  ribs. 

Some  of  the  foi'nis  fi'oni  (i(i.-<au  refen-ed  l)v  Zittel  to  /.  Grifpsi  resemble  closely 
I.  halti'cns." 

Tjipc. — From  the  Lower  Quadrafn^!  beds  of  Diilnien,  in  the  Paheontologicid 
Institute  of  the  University  of  Bonn. 

DutribiilvDi. — Senonian  of  Haldon,  and  \Vorl)arro\v  Bay  (Dorset),  and  Brighton 
(probably  zone  of  Mnrsupitcn  fcHfiKTuiarius).  Zone  of  Arthiocnmax  qiimhrifHs  of 
Mottisfont,  Ropley  (Hants),  East  Harnhani  (Salisbury),  Mount  Pleasant  near 
Andover,  Driffield,  and  Se\verl)v  (Vurkshirej.  Zone  of  iirli'muiti'lJii  nnh'tuii/iitu  nf 
Clareiulon  and  Farehani  (Hants),  Alum  Bay  and  SJiide  (Isle  of  Wight),  and  Xorwieli. 

Inocehamus  LOHATrs,  <li,](lfiif<^,  IS:')*;.     Text-figs.  5J-,  55. 

1836.     Inockramus  lobatus,  A.  Gohlfiiss.     Petref.   Grenii.,   vol.   ii,  \>.  118,  jil.  ex, 

fig.  :J. 
1877.  —  —         C.  Schliifer.      Palajoutograpliica,  vol.   xxiv,   p.  "27.5, 

pi.  xxxix,  figs.  1,  2. 
1882.  —  ~         H.  Schnuler.     Zeitsuhr.  d.  deutseb.  geol.  Gesellsclj., 

vol.  xxxiv,  p.  272. 
?  1888.  —  !.ff.  LOBATL's,  S.  NiA-itiii.     Los   Vostiges  Crc't.  iliuis  la   Kussie 

Centrale    (Mem.    Coniite    Gi'ol., 

vol.  V.  no.  2),  p.  'SI,  pi.  V,  fig.  12. 

—  —  LOBATUS,  G.  Mailer.     Jabrli.   d.  k.  preuss.  gcol.  Laudesaust. 

fur.  1887,  p.  415. 
1889.  —  —         E.  Hohap/rl.     Die  Mollusk.  Aachen.  Kreide  (Palse- 

outographiea,  vol,  xxxv),  p.  228. 
?  1894.  —  all.   LOBATUS,    K.   Jimho.     Kreideforuiat.    v.    Hokkaido    (Pal- 

seout.    Abliaudl.,    vol.    vi),   p.    44, 
pi.  viii,  fig.  11. 
1898.  —  LOBATUS,  (/.  Mullet-.     Mollusk.  Uiiterseu.  v.  Braunschweig,  n. 

Ilsede   (Abhandl.   d.  k.  preuss.  geol. 
Laudesaust.,  n.f.,  2.5),  p.  43,  fig.  10. 
■rl9Ul.  —  cf.  LOBATUS,  i'\  iS7«(///.     Jabrb.  d.  k.  preuss.  geol.  Laudesaust. 

fur  1900,  vol.  xxi,  p'.  93,  pi.  x,  fig.  3. 
1902.  —  LOBATUS,  A.   Wolli'iiuiiiii,  Liiueburg.  Kreide    (Abhaudl.  d.  k. 

preuss.  geol.  Laudesaust.,  n.f..  37), 
p.  71. 

1  '  Pal.  Frau?.  Teir.  Cret.,'  vol.  iii  (1846),  p.  516,  pi.  ccccx. 

-  Compare  also  /.  Crij)gi  var.  sulcata,  Eomer,  'Kreidebild.  v.  Texas'  (ls52),  p.  56,  pi.  vii,  fig.  2, 
aud  I.  Crijisianug,  Stoliczka,  'Pala?out.  Indica,  Cret.  Fauna  S.  ludi.i,'  vol.  iii  (1871).  p.  405, 
pi.  xxvii,  figs.  1 — 3  ;  pi.  xxviii,  fig.  2,  aud  T.  crassiis,  Petraseheck,  '  Jahrb.  d.  k.  k.  geol.  Eeicbsaust.,'  vol. 
liii  (1903),  p.  164,  pi.  viii,  fig.  4,  aud  Andert,  '  Inocerameu  d.  Kreibitz-Zittauer  Sandsteingeb.'  (It'll), 
p.  46,  pi.  iii,  fig.  4,  pi.  vi,  figs.  1,  2. 


IXOCERAMUS. 


2!>7 


1902.     IsoeKRXMUs  LoiiXTVi  J.  P.  J.  Utni.     M.>llu>k.    i    Diuiiiiuilcs   Kridtafl.   I. 

L;iiiirllil>r.,  p.  lOo. 
1C)0.5  —  —         T.  Wefjiier.     Zeitschr.    <1.    dcutsch.    f,'eol.    Gesellsch., 

vol.  Ivii,  p.  Itit,  fit,'.  7,  pi.  X,  figs.  1,  i, 
and  text- fig.  7. 
ic»0(!.  —  —         G.  Siiiol,!id-l.     Bull.  luteriiat.  Acad.  Sci.  Cracovi'-, 

p.  722,  pi.  xxvii,  figs.  16-18. 
l;i(»'.i.  —  --  J.  Kuind:     Ihi.l    (19Ui<).  p.  875. 


Fio.  54. — /noreraiiiiis  lobalui,  GoUlf.    Zime  of  Artinoeamaz  quadratut.  East  Leys,  Yorkshire.    BritUli  Miisvuni, 
No.  L23itHl.     Iiitfiiiiil  cnst  of  rijjlit  viilve;  p  isterior  wing  missin);.      x  J. 


Ih-srrijilinii. — Shell  very  im'i|iiilatcr;il,  (^^{(iiic,  compressed,  sliuflitly  eoiive.x  — 
till'  anterior  juirt  iiinrc  coiive.K  tiniii  llic  posterior  part;  nuicli  Iiij,^]ier  tliaii  Ioiil,'. 
Aiitero-dorsal    marginal    pait    .sloping  steeply.      \'entral   margin   eonve.x,    with   a 


298 


CRETACEOUS    LAMELLTBRANCHIA. 


shallow  .sinus  near  the  postero-ventral  angle.  Posterior  margin  nearly  straight, 
somewhat  oblique,  forming  an  angle  with  the  ventral  margin.  A  broad  shallow 
depression  extends  from  behind  the  umbo  to  the  postero-ventral  sinuosity  ; 
posteriorly  this  depression  is  limited  by  an  angular  ridge.     Behind  the  ridge  is  a 


Fig. 


-Jnocerainus  lobaius,  Orolilf.     Zone  of  Actiiiocumax  qiKulraliis,  Yorkshire.     York  Museum.     Part  of 

left  valve.      x  |. 


flattened  or  slightly  concave  wing-like  part  which,  owing  to   the   thinness  of  the 
shell,  is  often  not  preserved.     Umbones  acute,  near  the  anterior  end. 

Ornamentation  consists  of  concentric  ril)S  with  an  unsymmetrical  curvature  ;  in 
the  posterior  depression  the  ribs  bend  upwards,  forming  a  sinuosity,  and  on  the 
wing  the  ribs  bend  upwards  and  are  less  distinct  than  elsewhere.  The  concentric 
ril)s  are  of  two  sizes ;  large  ribs  occur  at  intervals  and  between  these  are  several 
sinallcr  ril)s. 


INOCERAMUS.  209 

Affinities. — Lioceramtis  nasiitti.'^,  Wegner,'  from  the  iSeiionian  of  Bosseiulorf  and 
Di'ilmeii,  is  allied  to  /.  hihafus.  See  also  /.  li)itpia,  T.  cardigsoiJesynwd  1.  inJn^rculntus 
(below). 

RemorJrs. — Only  iiii[iei  I'ect  casts  of  tins  species  have  been  seen,  but  it  is 
almndant  in  Yorkshire.  In  North  Germany  this  species  occurs  also  in  the  zone  of 
Marsupites  testudinanns. 

Type. — From  the  Lower  Senonian  of  Quedlinburg. 

Distribution. — Zone  of  Artiiinrmini.f  qmidrattoi  of  Sewerln',  Bessingby  and 
other  localities  in  Yorkshire. 


InOCEEAMUS  LINGVA,  GoJdfmii,  \^'M\.      Text- fig.  56. 

183(j.     Inoceramus  mngia.  A.  Guhlfiiff.     Pttref.  Germ.,   vul.  ii,  \<.  113.  j.l.  c-x, 

Hg.  5. 
1877.  —  —      C.  Schhiter.     Palseontograpliicu,    vul.     x.\iv,    p.     270, 

])I.  xxxix,  tigs.  3,  4. 

1898.  —  —      G.  Mailer.     Mollusk.  Uuterseii.  v.  Brauu.sehweig.  u. 

Ilsede  (Alihandl.  d.  k.  preiiss.  geol. 
Laudesanst.,  n.f.,  23),  p.  4-5,  pi.  v, 
fig.  8. 

1899.  —  —      V.Popovicl-Hatzeij.    Mi'in.  Soe.  gt'ol  de  France,  Pali'ont., 

vol.  viii,  pt.  3,  p    7. 
1902.  —  —      J.  P.  J.  Rant.      Mollusk.      Daumarks      Kridtafl.,      I. 

Laiuellibr.,  p.  102. 
19u5.  —  —      T.  Wegner.     Zeitschr.    d.     deutsch.     geol.     Gesellsdi., 

vol.  Ivii,  J).  168. 
19u9.  —  —      /.  Noicak.     Bull.  Iiiteruat.  Acad.  Sci.  Cracovie,  p.  875. 

Remnrks. — Thi.s  species  is  clu.sely  allied  to  /.  loliatns,  Goldfuss,  but  the  speci- 
mens at  present  available  are  not  sufficiently  perfect  to  enable  me  to  make  a  close 
comparison.  /.  liiiffiia  appears  to  differ  from  /.  lobatu.^  in  the  absence  of  the  ridge 
between  the  umbo  and  tlie  postero-ventral  angle,  in  the  absence  or  indistinct 
character  of  the  radial  depression  in  front  of  the  ridge,  in  the  greater  relative 
length  of  the  shell,  and  in  the  ribs  being  either  of  uniform  size  or  of  two  sizes  less 
distinctly  niiirked  than  in  1.  lubninsi. 

Type. — From  the  Senonian  of  Diilmen. 

Distribution. — Upper    Clialk    of    Birdsall,    Yorkshire.       Zone    of    Bclemititelln 


>  'Zeitschr.  d.  deuUch.  geol.  Gesellscli..'  vol.  Ivii  (1905),  p.  lt>7.  pi.  x,  fig.  3,  text-fig.  8. 


:5O0 


CRETACEOUS  la:\ielijbranchia. 


tiicroiuda    uF    Xorwich.       llccoidcd    l)j    Barrois    from    tlie    zone    of    Mar.-nipites 


te.'itiuUnarin.'<  of  Rottingdean. 


Fio.  50. — Inoceramus   Ihiyiia,    <!oI(lf.       Zone  of  Belemnilella  mucronata,  Norwich.      British  Miisouiii,  No. 

L2oy56.      Part  of  riufht  valve.     Natural  size. 


Ino('i;i!.\mi!s  cMiPissoiiiKs,  (lohlfitsfi,  183G.     Text-fig-s.  57,  58. 


1836.     Inoceramus  cardissoides,  ^.  Go/f(/'«.sjj.     Petref.    Gt'iiii.,    vol.    ii.    j).    11"2, 

pi.  ex,  fig.  2. 
18-41.  —  LOBATUS  var. /i.  CABDissoiDES,  J".  .(4.  i?n»ier.      Die    Verstein. 

d.  nord-deutscli.  Kreidegeb.,  |'.  ti'S. 
187(i.  —  cxnvisnoxnES,  I).  Bnuina.     Zeitsehr.    f.   d.    gesainiiit.    Natur- 

wiss.,  vol.  xlvi,  [I.  377. 
1877.  —  —  G.  Schiater.  Palaeoutographica,  vol.  xxiv,  p.  274. 

1888.  —  —  G.  Mailer.     Jahrb.    d.    k.    prouss.    geol.    Lau- 

d.'saust.  fiif  1887,  p.  415. 
1898.  —  —  G.  Miillev.     Mollusk.     Unterseu.     v.    Biaun- 

schweig  u.  Ilsede(Abliaudl.  d.  k. 
prt'uss.  geol.  Laudesaiist.,  n.f., 
25),  i>.  44,  fig.  11. 
19o2.  —  —  A.  WoUemaun.     Liiueburg.  Kreide  (lb  d.,  37), 

p.  71. 
1905.  —  —  T.  U'eyncr.      Zeitsehr.      d.      deutsch.      geol. 

Gesellscli.,  vol.  Ivii,  p.  109. 


IXOCERAMUS. 


301 


Nou  1882.     Inockkamus  cardissoides,  H.   Schroder.      Zeitscbr.     d.     deutscli.     geol. 

Gesellscb.,  vol.xxxiv, p.  271, 
j>l.  xvi,  fig.  1. 

Dei^criplion. — Sliell  very   inefniilatcral,   oblique,   moderately  convex,  -with   the 
anterior  marginal  part  sloping  rapidly.     Height  considerably  greater  than  length. 


Fta. 


Fio.  .-)S. 


\ 


^r 


.y 


UC^^•'■■'- 


p5^''^. .  > 


f  f, 


Fia    57 -7»ocei-amus  cardissoides.  Goldf.     Upper  Chalk  (proKably  zone  oi  ActinocauKix  quadratus).  near 

Speeton.     Sedgwick  Museum.     Left  valve.     Posterior  wing  missing.     Isatiual  size. 
Fio    58 -/no«.-a.»iis  cardissoides.  Uoldf.     Upper  Chalk,  probably  Kent.      British  Museum.  No.  98209. 

Part  of  left  valve.     Natural  size. 

Ventral  margin  convex;  anterior  margin  slightly  curved.  A  broad  concave 
depression  extends  from  behind  the  umbo  to  the  postero-ventral  extremity,  and  is 
limited  posteriorly  by  a  straight,  sharp  ridge,  behind  Avhich  is  a  wing-like  part  of 
the  shell. 

Ornamentation  consists  of  strong,  widely  separated  concentric  ribs,  with  a  steep 
ventral  slope  and  a  more  gentle  dorsal  slope;  in  the  interspaces  are  small  con- 
centric ribs,  which  arc  crossed  by  small  radial  ribs  giving  a  more  or  less  distinctly 

40 


802  CRETACEOUS   LAMELLIBRANCHIA. 

tuberculatc  cliaracter  to  the  larger  concentric  ril)?.  On  the  posterior  part  of  the 
shell  the  concentric  ribs  bend  sharply  npwards. 

Bcmarls. — Only  two  imperfect  specimens  of  this  species  have  been  seen  ;  it  is 
closely  allied  to  I.  Inhalnx  (p.  29G),  but  differs  in  the  presence  of  radial  ribs,  the 
greater  development  of  the  larger  concentric  ril)s,  and  in  the  greater  convexity  of 
the  valves. 

Tiiiv'. — From  the  Senonian  of  Quedlinlnirg. 

Distribution. — Upper  Chalk  ([)robably  zone  of  ^Irtinoi-intia.v  ijinatrafus)  near 
Speeton,  and  the  sonth  of  England  (probably  Kent). 


Inoceuamts  Tur.EKcur.ATi's,  sp.  nov.     Plato  lAY,  fig.  8.     Text-fig.  -59. 

1882.     Inoceramus  c.\rdissoides,  II.    Srlii-i'uh'r.      Zc-itxlir.      d.     deulscli.     geol. 

Gesellsch.,  vol.  xxxiv,  p.  271, 
pi.  xvi,  fig.  1  (Non  Goldfuss). 

Besi-rijifidii. — Shell  very  inequilateral,  ol)li(|ue,  niucli  higliei-  than  long;  dorsal 
part  moderately  convex,  ventral  part  only  slightly  convex.  Umbones  relatively 
small,  nearly  terminal.  Antero-doi'sal  ai-ea  flattened,  nearly  smooth.  A  rounded 
depression,  separated  from  the  posterior  Aving-like  part,  passes  from  the  umbo  to 
the  postero-ventral  extremity.  Hinge-line  forms  less  than  a  right  angle  with  the 
anterior  margin. 

Ornamentation  consists  of  numci'ous  concentric  ribs  which,  at  a  short  distance 
from  the  umbo,  are  crossed  by  radial  furrows,  so  that  the  ribs  appear  then 
to  consist  of  rows  of  tubercles  ;  on  the  sides  of  the  shell  the  radial  furrows, 
and  conserpiently  also  the  tubercles,  are  less  distinct  than  on  the  middle  of 
the  shell. 

AJfiiiities. — This  species  is  allied  to  /.  Inhntiis  and  /.  cardissoides,  but  differs  in 
the  greater  development  of  the  radial  ribs,  which  give  rise  to  a  tuberculate  type 
of  ornamentation ;  also  the  stronger  concentric  ribs  which  occur  in  I.  ca)xlissoides 
are  small  or  altogether  wanting.  The  English  specimens  agree  fairly  closely  with 
the  example  figured  by  Schroder  as  7.  cdrdissoidi's. 

Tijpc — In  Dr.  Rowe's  Collection. 

Distrilmtioii. — Upper  Chalk  (zone  of  Actiiwcamax  (jiiadratns)  of  Brighton,  and 
Sewerby  (Yorkshire). 


INOCERAMUS. 


303 


■A.  •«*»»> 


Fiii    '<'^ — /iicir.r.imus   (iifcfivii/.idis,   sp.   nov.       Zono   of    Aclinocamax   qHmlralus   of   Sewerby,    Yorkshire. 
Dr.  A.  W.  Kowe's  Collection.     Port  of  rij^ht  valve.     Natural  size. 


304  CRETACEOUS   LAiMELLIBRANCHIA. 


Inocekamus  UNDULATO-rncATiis,  lujiiicr,  1852.     Text-figs.  60,  01. 

1852.     Inoceramus  undulato-plicatus,  F.  llinner.     KreidcliilJ.  v.  Texas,  p.  i>9, 

pi.  vii,  fig.  1. 
1865.  —  DiGiTATUS,  F.  A.  Ei'niier.     Palaontographifa,  vol.  xiii,  p.  196, 

pi.  xxxii,  fig.  6. 
1873.  —  —        F.    Schmidt.       Mem.    Acad.    Imp.    Sci.    de    St. 

Pctersl).,  ser.  7,  vol.  xix,  no.  3, 

p.  25  (partim),  pi.  v,  figs.  10,  11  ; 

pi.  vi,  fig.  1,  2,  4,  6,  7  ;  pi.  vii ; 

pi.  viii,  figs.  9 — 15. 

1877.  — •  UNDULATO-PLICATUS,  C.    Scltliiter.       Paleeontographica,      vol. 

xxiv,  p.  270,  pi.  xxxviii, 
fig.  1. 

1878.  —  —  C.  Barrois.     Ann.  Soe.  gcol.  du  Nord, 

vol.  V,  p.  475. 
1894.  —  DioiTATUs,  A'.  Jiiiiho.     Palaeont.    Abhaudl.,    vol.    vi,    p.   43, 

pi.  viii,  figs.  8—10. 
1899.  —  ScHMiDTi,  B.  Michael.     Jahrb.  d.  k.  preuss.  geol.  Laudesanst. 

fiirl898,  vol.  xix,  p.  162,  figs.  1—4. 

Descyiptloii. — Shell  ovate,  much  higher  than  long,  very  inequilateral ;  the  early 
part  of  the  shell  of  small  or  moderate  convexity,  the  later  part  only  slightly  convex 
or  nearly  flat.  Hinge-line  forming  more  than  a  right  angle  with  the  anterior 
margin.     Umbones  terminal,  small,  curved  anteriorl}'. 

Ornamentation  consists  of  concentric  and  radial  ribs ;  the  former  are  more 
distinct  on  the  early  part  of  the  shell,  the  latter  on  the  later  part.  The  radial  ribs 
curve  outwards  from  a  line  between  the  umljo  and  the  postero-ventral  extremity ; 
they  have  rounded  summits,  and  arc  separated  by  broad  shallow  interspaces ;  a 
tubercle  or  rounded  elevation  may  l)e  developed  where  the  concentric  ribs  cross 
the  radial  ribs. 

A[fiiii,fiet>. — This  species  is  closely  allied  to  J.  Jiijitatns,  Schliiter  {nun 
Sowerby) . 

The  fact  that  in  some  specimens  the  early  part  of  the  shell  is  ornamented  with 
concentric  folds  only,  and  the  radial  ril)s  appear  on  the  later  parts,  suggests 
that  this  species  has  been  derived  from  one  with  concentric  folds  only,  in  a 
manner  similar  to  that  in  which  1.  sulcatus  has  arisen  from  /.  coiicentricus  (see  p. 
2G8) ;  the  specimens  at  present  available,  however,  do  not  enable  us  to  trace  the 
origin  of  I.  undulato-])licatiis,  but  it  seems  probable  that  it  has  descended  from  a 
flat  variety  of  I.  inconstans. 

Forms  from  Vancouver  Island  with  a  similar  type  of  ornamentation  have  been 


INOCEEAMUS. 


305 


referred  to  /.  )iu<hil<do-plicafiis  l)y  Whitoavcs,'  but  White-  doiil)ts  the  correctness 
of  the  identification.     1.  (lit'evsufi,  Stoliczka,''  is  anotlier  allied  form. 

Michael  does  not  accept  Schmidt's  and  Schli'iter's  identification  of  the 
specimens  from  Saghalien  and  North  Germany  with  Rnmer's  7.  VHthdato-plicatus, 
but  regards  them  as  belonging  to  a  distinct  species  for  which  he  proposes  the 
name  I.   Schniidti.     He,  howe\'er,  regards  /.  (h'lyri^Hs,  Stolic/.ka,  as  an  example  of 


F.u.  (il. 


Fig.  fill. 


Fig.  go. — Inoceramus  undulato-plieatus,  Kiiiii.     Sonoiiian.  UaMuu.     liritisli  MiLsciiiii,  Xu.   L17371.     Flint 

Ciist  of  part  of  right  valve.     Natural  size. 

Fig.  61. — Inoceramus  nndutnto-pUcnius,  Eiim.     Senonian.  llaMcm.     liritisli  Museum,  No,  1,1736'.'.      x   I. 

this  species,  consequently  it  \v;is  uniieecssary  to  inti'oduce  a  new  name.  The 
English  specimens  show  a  good  deal  of  variation,  and  after  comparing  them  with 
Rcimer's  and  other  figures  I  do  not  feel  able  to  accept  Michael's  view. 

jTv/jJC. — From  the  Chalk  of  Te.\as. 

Disfribitfiioi. — Senonian  of  TTaldon. 


•  '  Geol.  Siirv.  Canada,  Mesoz.  Fosf.,'  vol.  i  (1879),  p.  168,  pi.  xx,  fig.  2,  and  /.  digitatiis  (ibid., 
1903).  p.  395  ;  also  '  Trans.  Roy.  Soc.  Canada,'  ser.  2.  vol.  i  (189.5),  p.  121. 
«  'Bull.  U.  S.  Geol.  Surv..'  no.  51  (1889),  p.  37. 
'  '  PaloBont.  lodica,  Civt.  Fauna  S.  India,'  vol.  iii  (1871),  p.  407,  pi.  xxvii,  fiij.  (J. 


306 


CRKT A ( ' HOC S    LA^IE [ J JBE AXC ITTA. 


i 


Fig. 


Ii2  — Jnocei-nnius  umluhito-pUrntiis  var.  diqitatus.  SchUit.  Z..no  of  3/io-asf.T  ,-oi-an,j<il,nnn.  Suowclown 
Ci)llii>ry  Shalt.  Noniujjton,  near  Diivcr.  British  Museum,  N".  LliosU  (.liscoverea  and  presented  by 
Dr.  Malcolm  Burr).     Cast  of  part  of  left  valve,     x  J. 


V,' 


IXOCE  RAMUS.  307 


Inoceramvs  VKDii.ATo-i'i.K  Alls  ntv.  iMciTAns,  Srliliitrr,  1877.     Text-fig.  G2. 

1873.     Inoceramus  dioitatus,  F.  Sclmidt.    Mini.  Acad.  Imp.  Sci.  de  St.  Pt'tersb., 

sei'.  7,  vol.  xi.\,  no.  3,  p.  2.5  {2iartim), 
]il.  vi,  fi^-.s.  3,  5. 

1877.  —  —         C.  Schliiter.     Palseoutograpljica,  vol.  .xxiv,  p.  267, 

jil.  xx.wi. 

1878.  —  —         C.  Barniis.      Ann.    Soc.    fjcul.    du   Nord,   vol.    v, 

p.  475. 
1902.  —  —         A.  Wdlli'iiiinni.     Li'meburg.    Kreide   (Abliandl.    d. 

k.    preuss.    geol.    Landesanst., 
N.K.,  37),  p.  70. 

Revuirl-s. — As  was  pointtMl  out  liy  Scliliiter,  this  form  is  very  closely  allied  to,  and 
perhaps  not  separable  from,  /.  n whilato-plicatii s  ;  it  differs  from  the  latter  mainly 
in  that  the  posterior  ribs  are  strony-er  and  fewer  in  nunilier  than  the  anterior  ribs, 
but  the  early  parts  of  the  shell  are  very  similar  in  the  two  forms.  Until  more 
specimens  have  been  obtained  the  exact  relationships  of  the  two  forms  cannot  be 
determined,  and  for  the  present  it  seems  best  to  r(>o-ard  /.  digitittuH  of  Schliitcr 
{non  Sowerby)  as  a  variety  of  I.  nndiihitu-jtUcatiis. 

Distribafion. — Zone  of  Micratttev  cor-anr/niiiitm  of  Charlton,  Snowdown  Colliery 
Hliaft,  Xonington  near  Dover,  I'reston  near  Faversham,  and  Salisbury.  Zone  of 
Actinocamax  quailratun  of  Salisbury. 


Inoceuaml's   L\si\\ivKi,  Furli-iitson,  1819.     Plate  Lll,  figs.    1- — G;  Plate  LIII,  figs. 

1—7.     Text-figs.  63—85. 

17(i8.     OsTREOPiNNiTES,  J.  E.  I.  Walch.     Naturtfesc-liiclite     d.     Verstelu.,     vol.    ii, 

p.  142,  pi.  Di*»,  figs.  1—5. 
1819.     Inoceramus  Lamarckii,  J.  Parkinson.     Trans.  Geol.  Soc,   ser.   1,  vol.  v, 

p.  .5.5,  pi.  i,  fig.  3. 
1822.  —  CuviEKi,  J.  ::>oirt'rhi/.     Trans.    Linn.    Soc,    vol.    xiii,    p.  453, 

Jll.   XXV. 

—  —  Lamarckii,  G.  Mantell.     Foss.  S.   Downs,   p.   214,  pi.   xxvii, 

fig.  1. 

—  —  CnviERi,  Mantell.     Ibid.,  p.  213,  pi.   xxvii,  fig.  4,  pi.  xxviii, 

figs.  1,  4. 

—  —  IIkononiakti,  ^fantell.     Ibid  ,  p.  214,  pi.  xxvii,  fig.  8. 

—  —  Websteki,  MiiiilfH.     Ibid.,  p.  21»),  pi.  xxvii,  fig.  2. 

—  —  vvDVLJiTVS,  Mantell.     Ibid.,  p.  217,  jd.  .xxvii,  fig.  6. 

—  —  LATUs,  Mtnil-ll.     Ibid.,  p.  21(),  pi.  xxvii,  fig.  10. 

—  Catillus  Cuvikki.  .1.  ISronyniart.     lu   Cuvier's   Ossemens    Foss.,  vol.  ii, 

p.  601,  pi.  iv.,  fig.  10. 


308  CRETACKOUS   LAMELLIBRAXCHIA. 

1823.     Inuckramus  Cuvieri,  J .  de  C.  Soverlnj.     Miii.    Conch.,    vol.    v,   p.   59,    \'\. 

ceocxli,  fi^'.  1. 

—  —  Brongniarti,  Suicedii.     Ibid.,  vol.  v,  ]\.  GO,  pi.  ccxcxli,  figs. 

2.  3. 

1836.  —  Lasiarckii,  A.  Goldfuss.     Petref.  Germ.,  vol.  ii.,  p.   11-i,  ]>1. 

fxi,  fig.  "2. 

—  —  CuviEiti,  (Jultl/iiss.     Ibid.,  vol.  ii,  p.  Ill-,  pi.  ixi,  fig.  1. 

—  —  Brongniaeti,  Goldfues.     Ibid.,  vol.  ii,  p.  115,  pi.  cxi,  fig.  3. 

—  —  STRIATUS,  Gold/tiss.     Ibid.,  p.  115,  pi.  cxii,  fig.  2. 

183".     Catillus  lamarcki,  F.  BiijanVm.      Mrin.    Soc.    gi'ol.    de    France,  vol.   ii, 

p.  225. 

1837.  —  Cuvieri,  DnjanJin.     Iliid.,  vul.  ii,  p.  225. 

—  Inoceramus  Brongniarti,  IF.  Hisiiiijer.     Letliaea  Suecica,  p.  56,  pi.  xvii, 

fig.  11. 

—  —  CvYiERi,  Hii'iiKjer.     Ibi '.,  p.  5li,  pi.  xvii,  fig.  10. 

18-il.  —  Lamxrcku,  F.  A.  Riimer.      Die    Versteiu.    d.    uord  -  dentsch. 

Kreidegeb.,  p.  62. 

—  —  CuviEiii,  Ri'imer.     Ibid.,  p.  62. 

—  —  Brongniarti,  iio/Her.     Ibid.,  p.  61. 

?   —  —  TJNDULATUS,  Riiiiier.     Ibid.,  p.  63,  pi.  viii,  fig.  12. 

1846.  —  Cv\iBRi,  A.  E.  Reitss.    DieVersteiu.derbiihiu.  Kreideformat., 

pt.  2,  p.  25. 

—  —  Brongniarti,  Reuse.     Ibid.,  pt.  2,  p.  24. 

y  —  —  Cuvieri,  A.  Leymerie.     Statist,  gcol.  niin.  de  I'Aube,  Atlas, 

pi.  iv,  fig.  7. 
— ■  —  ANNULATUS,  Leymerie.     Ibid.,  pi.  iv,  fig.  4. 

—  —  Cuvieri,  A.  d'Orbigny.     Pal.    Franc.    Terr.    Crc't.,    vol.    iii, 

p.  520. 
1850.  —  Brongniarti,  H.  5.  GeMi^^z.     Das  Quadersandst.oder  Kreide- 

geb. iu  DeutscLland,  p.  172. 
r'   —  —  Cuvieri,  A.  d'Orhigiiy.     Prudr.  de  Pal.,  vol.  ii,  p.  250. 

1850.  • —  —        R.  Kner.     Kreidemerg.    v.    Lemberg    (Haidinger's 

Naturwiss.   Abliandl.,    vol.    iii,   pt.   2), 
p.  28. 
1854.  —  Lamarckii,  /.  Monts.     Cat.  Brit.  Foss.,  ed.  2,  p.  169. 

—  —  Cuvieri,  3Iorris.     Ibid.,  p.  169  (parlim'). 

—  —  Brongniartii,  Morris.     Ibid.,  p.  169. 

—  —  UNDULATUS,  Morris.     Ibid.,  p.  170. 

—  - —  Websterii,  Morris.     Ibid.,  p.  170. 

1863.  —  Cuvieri,  A.  v.  Siromlieck.     Zeitsclir.  d.  deutscli.  geol.  Gesell- 

scli.,  vol.  XV,  p.  124. 

—  —  Brongniarti,  Siromleclc.     Ibid.,  vol.  xv,  p.  121. 

—  —  —  R.  Drescher.     Ibid.,  vol.  xv,  p.  352. 

?1869.  —  Damarki,  E.  Favre.     Moll.  Foss.  de   la   Craie  de  Lemberg, 

p.  134. 
1870.     Inoceramus  Brongniarti,  F.  Ri'nner.      Geol.  v.  Oberscbles.,  p.  316,  I'l. 

xxxiv.  fig.  13. 


IXOCERAMUS.  309 

1872.     Inoceeamus  Bkongniarti,  Jf. -B.  6'e>i«i7z.     Das    Elbthalgeb.    in    Sachsen 

(PalBeontogrnphica,    vol.    xx, 
pt.    2),    p.   48,    pi.    xi,    figs. 
3—10,  pi.  xiii,  fig.  3. 
P    _  —  CuviERi,  Geiiiltz.     Ibid.,  p.  48  (partim),  pi.  xiii,  fig.  8. 

Ig73  —  Brongniakti,  Get/iite.     Neues  Jalul).  fiir  Miti.,  etc.,  p.  10. 

s-    —  CuviERi,  Geiiiih.     Ibid.,  p.  15. 

p    —  —  Lamarcki,  Gelnitz.     Ibid.,  p.  18. 

i*  1875.  —  LATUS,  G.  Drcorq.     Assoc.    Frauc.    Avauc.    Sci.   (Lille,  1874), 

p.  369. 
J877.  —  CuviERi,  C.  ScJdiiter.     Palseontographica,  vol.  xxiv,  p.  266. 

—  Brongniarti,  C.  SclMter.     Ibid.,  vol.  xxiv,  p.  263. 

_  _  —  A.  Fritsch.     Stud,  ill!  Gebiete  der  biihm.  Kreide- 

format.,ii,  Weisseuberg.  u.  Mal- 
nitz.  Schicht.,  p.  130,  fig.  111. 
187g_  ._  —  G.Behrens.   Zeitschr.  d.  deutscL.  gee).  Gesellsch., 

vol.  XXX,  p.  256. 
p    _  _  UNDULATUS,  C.  Bavrois.     Auu.    See.    gcol.    du   Nord,   vol.   v, 

p.  407. 

1881.  (Mytilites)   problematicds,  J?.  Etheridgr,   iu  Peuuing  and 

Julies-Browne,    Geol.    Cam- 
bridge, p.    143,    pi.    iii,  figs. 
9,  10,  11. 
p  1883.  —  Brongniarti,  A.  Frilsch.     Slud.  im  Gebiete  der  bOhm.  Krei- 

deformat.,  iii  Iserschicht.,  p.  110, 
fig.  80. 
1888.  —  CuviERi,  4.  PeroH.     Hist.    Terr.    Craie  S.E.    Bassin   Anglo- 

Parisien,  p.  156. 

—  Brongniarti,  Peron.     Ibid.,  p.  157. 

—  rNDULATUS,  Peron.     Ibid.,  p.  15/. 

P1889.  —  CuviERi,  ^.  Pri7«c/(.     Stud,  im    Gebinte   der  biilim.   Kreide- 

format.,  iv,  Teplitz.  Scliicht.,  p.  82, 
fig.  74. 
p    _  Brongniarti,  Fritsch.     Ibid.,  p.  81,  fig.  72. 

1892.  —  CuviERi,  E.  Stulley.     Die    Kreide    Sebleswig-Holsteins  (Mit- 

theil.  a.  d.  miu.  lustitut  Kiel,  vol.  i.), 
p.  241. 

1893.  _  Brongniarti,  E.  Michael.     Zeitschr.  d.  deutscb.  geol.  Gesell- 

sch., vol.  xlv,  p.  242. 
1897.  _  striatus,  H.  Woods.     Quart.  Jouru.  Geol.  Soc,  vol.  liii,  p.  381, 

pi.  xxvii,  fig.  13. 
_  _  CuviERi,  B.  Lconhanh     Pateontographica,  vol,  xliv,  p.  49. 

_  —  Beononiakti,  Leonhard.     Ibid.,  vol.  xliv,  p.  47. 

1899  _  _  J.  Simionescu.     Fauna    Cret.     Super.     Urmos, 

p.  27. 
?    _  _  CuviEEi,  SimioiiescH.     Ibid.,  p.  27,  pi.  ii,  figs.  8,  9. 

P1901  —  a£f.    CuviERi,    H.    ImJceller.      Paloeontographica,    vol.    xlviii. 

p.  34. 

41 


310  CRETACEOUS   LAMELLIBRANCHIA. 

llMll.     Inoceramus  CuviERi,  J^.  (S7((n»i.     Jalnb.    d.   k,  jireuss.  g-eol.   Landesanst., 

fur  1900,  vol.  xxi,  p.  92,  pi.  x,  fig.  1. 
in02.  • —  —       A.  WuJIemann.     Liiiiebuif,'.   Kreide  (Abhandl.  d.  k. 

preuss.  gc'ol.  Landesanst., n.f.,  37), 

p.  67. 

—  —  Brongniarti,  Wollemann.     Ibid.,  p.  G6. 

1903.  —  —  W.  Petmscheck.     Jahrb.  d.  k.  geol.  Kfichsanst., 

vol.  liii,  p.  161. 

—  —  CuviERi,  PefraschecJc.     Ibid.,  p.  162. 

1904.  —  i^ATVs,  E.  T.  Ncwti  n   and   A.  J.   Juices-Browne.      In   Jukes- 

Browne,  Cret.  Rocks  of  Britain,  vol.  iii, 
p.  448  (partim). 

—  —  COBDIFORMIS,  C  ^ ('*•(»;/'"•     Boll.  Soc.  geol.  Italiana,  vol.  xxiii, 

p.  189,  pi.  iv,  figs.  6—9. 

1908.  —  Ctivieri,  a.  Sfojanoff.      Ann.  gi'ol.  niin.  Russie,  vol.  x,  p.  121. 

1909.  —  —         J.Nowal:    Bull.  Internat.  Acad.  Sci.  Cracovie,  p.  875. 
1911.              —           LATUS,  W.  Ro/jala.     Ibid.  (1911),  p.  172,  pi.  iv,  figs.  9,  10. 

—  —  KoEGLERi,  H.  Andert.    Inocerameu  d.  Kreibitz-Zittauer  Sand- 

steingeb.,  p.  57,  pi.  v,  fig.  6,  pi.  i,  fig.  6. 

Nou  1827.  —  CvYiERi,  S.  NHsson.     Petrific.  Sueeana,  p.  19. 

?  —       —        Catillus  Brongniarti,  Nthsoii.     Ibid.,  p.  19. 

—  1832.     Inoceeamus  undulatus,  C.  H.  v.  Zieten.     Versteiu.  Wiirttembergs,  p.  96, 

pi.  Ixxii,  fig.  7. 

—  1846.  —  Lamarckii,  A.  iVOrhiijtiy.     Pal.  Fian^.  Terr.   Cri't.,   vol.    iii, 

p.  518,  pi.  ccccxii,  figs.  1 — 3. 
?   —     1847.  —  CcviERi,  J.  JI/»7/er.     Petref.  der  Aaclien.  Kreidef.,  pt.  1,  p.  31. 

?  —      —  —  Brongniarti,  MiiUer.     Ibid.,  pt.  1,  p.  30. 

—  1850.  —  Lamarckii,  /.  dc  C.  IScverli!/.     In   F.    Dixon,    Geol.    Sussex, 

p.  365(p.385,ed.2),pl.xxviii, 
fig.  29  (=  J.  inconstans). 

—  1866.  —  liA'M  AUCKi,  K.  A.  Z  iff  el.    Bivalv.  d.  Gosaugeb.  (Denkschr.  d.  k. 

Akad.  d.  Wissensch.  Wien,  Math.- 
nat.  CI.,  vol.  xxiv),  pt.  2,  p.  99  [23], 
pi.  XV,  fig.  6. 

—  1872.  —  —  H.  B.  GeinHz.     Das  Elbtlialgeb.  in  Sachseu  (Pal- 

ffioutograpliica,  vol.  xx,  pt.  2), 
p.  50,  pi.  xiv,  fig.  1  (fig.  4  = 
gaxonicvs,  Peti'ascheck) . 

—  —  —  CuviERi,  Geinitz.     Ibid.,  p.  48,  pi.  xiii,  figs.  6,  7. 

?—     1872—3.        —  STRiAivB,  Geinifz.     Ibid.,  pt.  1,  p.  210,  pi.  xlvi,  figs.  9— 13  ; 

pt.  2,  p.  41,  pi.  xiii,  figs.  1,  2,  9,  10. 

—  1899.  —  undulatus,  J.  Simionesni.     Fauna  Cret.  super.  Uruios,  p.  26, 

pi.  iii,  fig.  2. 

—  1904.  —  Beongniaetii,  C  yli7a(/A(.     Boll.  Soc.  geol.  Italiana,  vol.  xxiii, 

p.  192,  pi.  iv,  figs.  3 — 5. 

—  1911.  —  CuviEEi,  H.  Andirt.      Inoceramen  d.  Kreibitz-Zittauer  Sand- 

steingeb.,  p.  44,  pi.  ii,  fig.  2. 


INOCERAMUS.  311 

Dctirriptiu)i. — Shell  inequivalve,  very  inecmilateral,  of  slight,  moderate  or 
considerable  convexit}-,  sometimes  inflated.  Height  greater  than  length.  Hinge- 
line  of  variable  length  in  proportion  to  the  height  of  the  shell,  forming  more  than 
a  right-angle  with  the  anterior  margin.  Umbones  terminal,  cnrved  inwards  and 
more  or  less  forwards ;  the  left  umbo  more  prominent  than  the  right.  Anterior 
marginal  part  of  valves  flattened,  more  or  less  nearly  perpendicular  to  the  plane 
of  the  valves,  either  limited  by  a  sharp  edge  from  the  flanks  or  without  a  definite 
boundary.     Anterior  ear  developed  in  some  flat  varieties. 

The  concentric  folds  may  be  absent,  indistinct,  or  moderately  or  strongly 
developed,  with  the  dorsal  and  ventral  slopes  similar  or  with  the  ventral  slope 
steeper  than  the  dorsal.  Usually  the  folds  are  regular,  but  are  not  continued  on 
to  the  posterior  ear.  The  curvature  of  the  folds  is  often  nearly  symmetrical ; 
its  convexity  on  the  convex  and  on  some  of  the  flat  forms  is  small,  but  is  greater 
on  the  flat  forms  with  a  relatively  short  hinge.  The  growth-lines  are  distinct 
and  variable  in  number,  and  are  sinuous  where  they  pass  on  to  the  posterior  ear. 

RemarJiS. — The  forms  included  in  this  species  show  a  great  amount  of 
variation,  and  seem  in  that  respect  comparable  with  some  species  of  Mlcranfer  and 
Echinoconis.  Several  of  the  varieties  have  been  described  as  distinct  species,  but 
the  stud)'  of  a  large  series  of  specimens  has  shown  so  many  intermediate  forms 
that  one  can  only  regard  the  varieties  as  modifications  of  a  very  plastic  species. 
The  features  in  which  variation  is  most  marked  are  the  convexity  of  the  valves, 
the  number,  strength,  and  curvature  of  the  concentric  folds,  the  distance  between 
the  growth-lines,  the  size  and  distinctness  of  the  posterior  ear,  and  the  height  of 
the  shell. 

Some  forms  of  this  species  are  only  slightly  convex  (Plate  LIII,  fig.  7,  Text- 
figs.  73 — 83),  so  that  in  large  specimens  considerable  portions  of  the  shell 
approach  flatness.  In  other  forms  the  valves  are  moderately  or  considerably 
convex,  and  sometimes  inflated  (Plate  LII,  figs.  4,  5,  Text-figs.  G3 — 68).  The 
amount  of  convexity  may  remain  nearly  uniform  throughout  the  growth  of  the 
shell,  or  the  earlier  part  may  be  only  slightly  convex  and  the  later  part  very 
convex — in  such  cases  the  early  part  resembles  the  adult  shell  of  the  large  flat 
varieties  (Figs,  (il,  Go).  The  two  valves  may  be  of  nearly  ecjual  convexity  (Plate 
LII,  fig.  5),  or  the  left  valve  may  be  very  convex  whilst  the  right  valve  is  only 
slightly  convex  (Plate  LII,  fig.  G). 

The  concentric  folds  vary  in  strength,  niunber,  form,  curvature  and  regularity. 
In  the  majority  of  cases  the  folds  are  prominent  and  form  strong  ridges  (Figs.  (SS, 
G9,  7S,  82,  84-),  but  they  may  become  only  gentle  undulations  (Figs.  74,  77,  81), 
and  are  sometimes  indistinct  or  absent  (Figs.  73,  7-J,  7G,  71>)-  The  dorsal  and 
ventral  surfaces  of  the  folds  may  slope  equalh',  or  the  ventral  slope  may  be 
steeper  tiiaii  the  dorsal,  giving  a  step-like  appearance.     The  crest  of  the  fold  is 


312 


CRETACEOrS   LA:\IETJJBRAX('H1A. 


Fig.  63. — Inoceramiis  ifiHiariAi,  Park.  The  type.  Uppor  Chalk  (probably  zouo  of  Jllicriis/cr  cor-a>ig«iHKin), 
near  Dover.  British  Museum,  No.  L9S0] .  Left  valve  and  dorsal  view.  Part  of  the  posterior  ear  is 
concealed  by  flint.    Natural  size. 


Fig.  6!-.— /iioi-craoiiis  Lamarcl:i,  Park,     Anterior  view  of  specimen  shown  in  Fisj.  Go.      x 


IXOCERAMUS. 


313 


Fio.  05 


Fig.  67 


Fig.  Go. — Iiioceramiis  Lamarcii,  Park.     Upper  Clialk  (probably  zone  of  Holaster  planum),  Swaffliam,  Norfolk. 
Norwich  Museum,  No.  3354.     Ki^ht  valve.      x  i. 

Fig.  67. — Iiirn-enimm  Lamarcld,  Park.     Upper  Chalk  (zone  of  Holaster  2>lanii.\),  Newmarket.     Sedgwick 
Museum,  Cambridge.     Kight  valve.     Natural  size. 


Fig.  Tfi. — Inorci-oiiiii.s  I.iniKinki,  I'ark.  The  original  of  /.  Lnmarcki,  Mantell,  'Fobs.  S.  Downs,'  p.  214, 
pi.  xxvii,  fig.  1.  Middle  Chalk  (priibal>ly  zone  of  Terebratiilimi  latn),  near  Lewes  (probably  Mailing), 
liritish  Museum,  No.  4753.     Kight  valve.     Natural  size. 


114 


f'T^ETACEOUS   LAMELLIBRANCHIA. 


Fio.  68. — Inuceramns  Lamiurki,  I'ark.  The  type  of  /.  Bi-oiigniarti,  Mautell,  '  Foss.  S.  Downs,'  p.  214, 
pi.  xxvii,  fi^.  8.  Prom  Lewes  or  Brighton,  probably  zone  of  Micrasler  cor-anguintim.  British  Museum, 
No.  4751.     Left  valve  anil  dorsal  view.     Natui-al  size. 


Fio.  69. — Inoceramtis  Lamarcki,   I'ark.      The  original   of   /.   Cuvieri,  Mantell,   '  P'oss.  S.   Downs,'  p.  21.3, 
pi.  xxviii,  fig.  4.     Zone  of  Mi>ni.v(i'r  cor-antjiiinum,  Southerani.     British  Museum,  No.  L22094.      x  |. 


INOCERAMUS. 


315 


KiQ.  70. 


Fi. 


Fig.  70. — Inoceramus  Lamarchi,  Park.      The  original  of  I.  Bronr/nUnti,  Suvvfrby,  '  Min.  Conch.,'  vol.  v, 

p.   60,   pi.   ccccxli,   &g.   2.    Chalk.     Locality   and  horizon   unknown.     British   Museum,   No.    13265. 

Right  valve.     Natural  size. 
Pig.  71. — /noceramws  Lamarcki  var.  IVebsteri,  Mant.     The  type  of  /.  JJ'ebsteri,  Mantell,  '  Foss.  S.  Downs,' 

p.  216,  pi.  xxvii,  fig.  2.     Upper  Chalk  (probably  zone  ot   Micraster  cor-testudinarium) ,  South  Street, 

Lewes.     British  Museum,  No.  4-7o9.     Left  valve.     Natural  size. 

Fig.  73. 


Fio.  72. 


y 


.jmt 


Via.  72. — Inoceramus  Lamarcki  var.  Websteri,  Mant.     Upper  Chalk,  Swaffhaui,  Norfolk.     Norwich  Museum, 

No.  32!»S.     Left  valve  and  anterior  view.     Natural  size. 
Fia.  73. — Inoceramus  Lamarcki  var.  Cuvieri.  Sow.     The  type  of  inoceramus  Cuvieri,  Sowerby,  'Trans.  Linn. 

Soc.,'  vol.  xiii  (1822),  p.  453,  pi.  xxv,  figs.  2,  3,  and  'Min.  Conch.,'  vol.  v  (1H23),  p.  5!l,  pi.  ccccxli,  fig.  1. 

Middle   Chalk   (zone  of  Terebralulina   lata),   Koyston.      British   Museum,   No.  -13204.     Left  valve. 

Natural  size. 


316 


CRETACEOUS   LAMELLIBRANCHIA. 


usually  roimded,  l)ut  in  one  variety  {WtJisteri,  Mantell,  Plate  LTII,  figs.  1,  2, 
Text-figs.  71,  72)  it  possesses  a  sharp  edge.  When  the  folds  are  absent  the 
growth-rings  become  more  regular.  The  curvature  of  the  folds  is  usually  small 
in  the  more  convex  S})ecimens,  but  often  greater  in  the  less  convex  forms.  The 
curvature  is  often  nearly  symmetrical,  but  when  the  posterior  ear  is  indistinctly 
limited  it  tends  to  become  unsymmetrical. 

The  degree  of  development  of  the  posterior  ear  varies  considerably.     In  some 
forms  it  is  only  indistinctly  limited  (Plate  LIII,  fig.  7,  Text-fig.  (38),  and  tlien  the 


{' 


Fig.  74. — Inoceramus  Lamareki  var.  Ciivieri,  Sow.  Upper  Chalk  (zone  of  Micraster  cor-anguinum).  Camp 
Hill,  near  Salisbury.  Dr.  Blackuioro's  Collection.  Portion  of  a  large  left  valve  ;  posterior  and  ventral 
parts  missing,      x  |. 

folds  and  growth-lines  are  continued  with  but  little  alteration  in  curvature  on  to 
the  ear.  In  other  cases  the  ear  is  larger  and  more  or  less  distinctly  limited  from 
the  rest  of  the  valve  (Plate  LII,  fig.  4,  Text-figs.  03,  (35,  66,  79,  81,  82) ;  in  such 
cases  the  folds  and  growth-lines  bend  inwards  at  the  limit,  and  the  umbonal  part 
of  the  valve  is  often  narrower  and  more  acute.  In  a  few  large,  flat  forms,  an 
anterior  ear  is  developed  (Fig.  74). 

The  anterior  flattened  area  varies  in  size  and  in  the  distinctness  of  its 
boundary.  It  may  be  nearly  perpendicular  to  the  plane  between  the  valves 
(Fig.  81),  or  may  be  slightly  concave  (Figs.  G3,  66,  79),  or  slope  outwards  (Figs. 


INOCERA.AirS. 


31 : 


74;  79).  Ill  some  varieties  the  iii-e;i  forms  a  sliai'p  edge  -witli  tlie  sides  of  the 
valve  (Fig.  81),  in  otliers  tlie  l)(>midar\'  is  curved  and  tlie  limit  of  the  area  is 
indistinct  (Fig.  85). 

In  the  type  of  /.  Lamarclci,  Parkinson  (Fig.  03),  the  shell  is  inflated,  and  the 
posterior  ear  well  developed  and  sharply  limited.  In  forms  like  T.  Brour/niarfi 
Sowerby   (Fig.  70,  PI.    LII,  tig.  4),  the  posterior  ear  is  also  well  developed,  but 


^» 


^/> 


^ 


Fig.  75. — Inoceramiis  Liimarrki  v.ar.  Cuvieri,  Sow.     Upper  Chalk,  Southevam,  l/owos.     Biightou  Museuin, 
No.  340.     Poi-tion  of  :i  Ifft  valve  ivseiiibliiijf  tho  type  of  I.  latus,  Mant.      x  |. 

not  so  sharply  limited  as  in  the  type  of  I.  Lamarcki.  Mantell's  /.  Lamarclci 
(Fig.  66)  is  similar  to  /.  Bronfjniarti,  Sowerby,  but  has  less  prominent  folds  and 
a  more  concave  anterior  border.  /.  Brougniarfl,  Sowerby,  passes  gradually  into 
forms  like  the  type  of  /.  Bi-ninjiiiarfl,  Mantell  (Fig.  68),  in  which  the  limit  of  the 
posterior  ear  is  somewhat  indistinct.  Other  varieties  possess  similar  strong  folds 
but,  have  less  convex*  valves  (as  in   /.  Cuvieri,  Mantell,  Figs.  69,  84),  and  these 

'  lu  some  cases  the  smaller  convexity  may  be  due  to  pressure  which  gradually  changed  the 
shape  of  the  shell.  When  no  fractures  are  seen,  flattening  appears  to  be  indicated  in  some  cases  by 
the  growth-lines  cutting  the  folds  obliquely. 

42 


ns 


CRETACEOUS    LAMEi.LlHRANCllJ A. 


pass  into  forms  with  i.ulistinct   folds  like  the  tvpe  of    /.   Curu'ri,  Sow^rhy  (Eig. 
7:}),  iiiul  in  some  cases  tht-  fohls  disappear  altogetlier. 


'k 


Fig.  ^G.-Inocera,nus  Lamarcki  va..  CuvicH  Sow.     The  typeof  I^'^^!'^^^^'^^'''^^'^^- 
p.  216,  pi.  xxvii,  &s-   10-     Uppci'  Chalk,  near  Brighton.     Britisli  MusLum,  s\o. 
Natural  size. 

I.  Wehster!,  Mantell  (Figs.  71,  72),  Las  the  posteriov  ear  fairly  well  developed, 
but  not  distinctly  limited,  and  resembles  /.  Urongniarti  of  Planted  ;  it  is 
characterised  l,v  the  thinness  of  the  shell  and  the  sharp  ridge-Lko  folds,  but  forms 


INOCK  RAMUS. 


319 


mteniiLMliate  between  tliis  type  and  those  witli  runndetl  folds  occur.  It  may 
be  convenient  to  adopt  lor  this  variety  the  name  /.  TjH tmi rrJ:'i  ww.  ]V('hsfi'ri.  It 
appears  to  occur  mainly  in  the  zone  of  Micraster  cor-testadiimrium. 

].  tniiliilnfns,  ]\[antell  (PI.  LIII,  fio^.  3),  resembles  small  forms  of  I.  BroiKjinarll, 
Sowei'l)y,  but  the  folds  are  much  smaller,  more  numerous,  and  less  conspicuous, 


an 


d  f 


le  shell  IS  thicker  tlian  usual. 


i. 


Fig.  77. — Iiiocohhiks   Lmiinrchi  var.   Citvieri,  Sow.       U|>|)(  r   Chalk   (zone  of  Holiisler  ji/miiis),  Si\:ifTli:iiii. 
Niiil'ulk.     Norwich  Mtiscuiii.     I.oft  valve.      x  J. 

Some  small  forms   (IM.    Id  1 1,  figs.   4— G),  found    in    the    .Middle  Chalk   and  in 

the  zone  of  Iluldstcr  jihiniis,  which  may  1k>  named  /.  Ldinnrrkl  var.  apicdlix,^  have 

neai-ly  eipial  valves,  more   prominent   ami  more  distinctly  incurved  umbones,  with 

the  folds  indistinct  or  al)sent,  but  these  forms  pass  into  others  with  distinct  folds. 

In  some  of  these  small  forms  the  umbo  is  curved  anteriorly  (Plate  LIII,  tiu^.  -I). 

'  An  I'Xiimiik-  of  tlii.s  I'l-am  the  Chalk  Rock  was  figured  in  tlie  '  Quart.  Ji>urn.  Geol.  Soc,"  vol.  liii 
(18St7),  p.  381,  pi.  .\xvii.  fi-.  1:;. 


320 


CllETxVCEOUS   LAMELLlBliA.XCUIA. 


/.  hitns,  ^Mantel]  (Fig.  76)  is  a  large,  slightly  convex  form  in  wliicli  the  folds 
have  almost  disappeared.  In  the  type  (Fig.  7'))  the  postero-dor.'^al  part  of 
the  valve  is  missing,  so  that  in  ]\ranteirs  figure  the  umbonal  part  of  the  valve 
appears  to  be  more  acute  than  it  really  is  (compare  Fig.  75). 

T.  Guvieri,  Sowerby  (Fig.  73)  is  only  slightly  convex,  with  indistinct  folds,  and 
is  often  of  large  size.  The  angle  formed  by  the  antei'ioi-  margin  and  \\\v  hinge- 
line  is  rather  larger  than  usual,  and  a!i  anterior  ear  niav  be  developed  ;  other  forms 


Via.  78.— /iiocccamns  Lamarcki  var.  Cuvieri,  Sow.     Upper  Chalk,  Lewes.     Sedgwick  Musouin,  CambiiJfjo. 

Eiglit  valve.     Natural  size. 

are  similar  (Fig.  7'.'),  but  have  a  smaller  angle  between  the  anterior  margin  and 
the  hinge,  and  these  pass  into  forms  with  more  distinct  and  eventually  with 
strong  folds  (Figs.  77,  78,  82).  The  varieties  similar  in  form  to  Sowerby's  type, 
l)ut  with  or  withont  folds,  may  be  termed  /.  Lamarcld  var.  Cuvieri  (Plate  LIII, 
tig.  7,  Text-figs.  73 — 84).  The  hinge  in  large  specimens  of  this  variety  (Fig.  80) 
is  of  great  thickness,  and  portions  of  it  are  often  founil  separately.  It  is  thickest 
near  the  undx),  and  l)ecomes  thinner  towards  the  posterior  end.  The  ligament 
pits    ai-e   numerous,    shallow,   and   two,   three,  or   more  times  highei'   than    long, 


INOCERAMUS. 


321 


i 


Fio.  79. — Inoccramus  Lamorchi  var.  Cuvieri,  Sow.     Zone  of  Holnster  planus.  Borstal.     Jlr.  Dibley's  Collec- 
tion.    Ei^ht  valve  and  anterior  view,      x  5.  9 


Firi.  SO.  — Iiioeeramas  Lamareki  var.  Cuvieri,  Sow.     Zone  of  Terehratnlinn  /<i/ii.Royston.     SeJ>jwiek  Mu.seuni, 
Cambridfje.     Portion  of  left  liinfje.     Natuml  size. 


,'322 


CKKTACKOL'S    LA.M  KU  J  I'.iiAXCII  I  A. 


ivacliiiiL;-   tlicir    iniixiimmi    lici^lit    not    far    fVdin    the    iiiiiho.      'I'lio    variety    Chiricri 
ranges  from  tlie  zone  oF  Trrcl'i-iihiliiin  lata  to  tlie  zone  of  Micrai<ter  cor-anguinum. 

T.  M(i)itdli,  de  ]\Ierce_v,'  from  the  zone  of  Min-'isler  cor-iinf/ninum,  appears  to 
])(■  a  large  form  of  /.  Lauiarchi  var.  CiLcleri,  in  wliieli  an  anterior  ear  is  developed; 
it  is  similar  to  a  specimen  (Fig.  74-)  obtained  i)y  Dr.  Blackmore  from  the  zone  of 
Mirrtisifpf  (■iij--iiii)iiiiiinn/  of  Camp  liill  neai-  Salislmrv. 


1..__-9 


^^^-: 


y 


Kk;    si. — Iiiorpi-niiiiK   l,,iiiH(irli   vnr,    C'lit'icri,  Sow.     Z.>no  of    Tci-fhi-iilalinii   lutii,  Bluo   Bi-ll  Hill,  liui-liam. 
Mr.  Dililcy's  Cdllctti.Mi.      Left  Viilvc  with  imstcriur  part  luissiii!,' ;  antcrim-  view  of  the  same  valve.      x  J. 

7.  /ii-i-i-i)st,ifiis.  .Midler-  ('especially  tlie  example  tignred  liy  IV'traseheek''),  seems 
to  be  closelv  allied  to  f.   I,ii iiKirfl/i  xar.    II  ('/(.s7r/-/. 

Ti/pc!^. —  /.  I]iiinitri-l-i,  I'ai'kinson  ( l''ig.  (>:')),  IVom  near   Dover  ( [iroKalily  /.one  of 

'  •  Mem.  8ne.  Linn.  Nonl  .Ir  la  Knuiei','  vol.  iv  (1877),  p.  o-Jt.  [ils.  i.  li.  Barrel-.  '  .\.un.  Sne. 
^■eol.  Nunl,"  v.il.  vi  (187lt).  1'.  4.')t.  pi.  iv. 

-  '  Jalnli.  (1.  k.  pivuss.  <,'('(.!.  LiUKlo^aiist.  u.  Bi'ri,'aka<l.  fiir  1887'  (1888),  p.  413,  pi.  xvii,  fig.  3. 

=  •  Jaliili.  il.  k.  k.  t:eoi.  Reielisanst.,'  vol.  hi  (IHUC),  p.  Iti3,  fiij.  2.  Also  I.  Glatziic  ami  /.  Klelin, 
,\n(lci-t.  •  Iiioeeraincn  .1.  Kreil.it/,-Zitlaufr  Samlstciiigcl).'  (lUIl  ),  ].p.   ts,  r,->.  pi.  i,  fig.  3,  pi.  ii,  tig.  8. 


iX()ri-:u.\:\irs. 


323 


Micra.'iter  ciir-auijiiliunii)  ;  in  the  Ui'iti.-li  Afuscuiii,  Xo.  I/JSUJ.      This  siieciineii  was 
first  I'ccogiiiscd  as  the  original  of  Parkinson's  figure  hv  Mr.  (".  D.  Sherboni. 


/ 


,^' 


/ 


Fio.  SJ.— //locfi-rtiiiKs  LoDuiixli  Viir.  C'«i-i«M-i,  Sow.     Chalk;  Imwlity  ami  horizon  unknown.     BritUli  Museum, 

No.  LaSiW'J.     Kijjlit  valve,      x  {. 

].  .C'li fieri,  Sowerliy  (Fig.  7o),  from  the  Mi(hlK>  Chalk  of  Royston  (zone  of 
Terchratnliaa  lata);  in  thi"  British  Museum,  Xo.  4o:2(Jl-. 

/.  Lumarrhi,  >faiite]l  (Fig.  00),  from  the  ^Middle  Clialk  near  Lewes  (probably 
from  dialling,  zone  of  TvrcbmiaUna  lata)  ;  in  tlie  British  Museum,  Xo.  47-Jo. 


324 


CRETACEOUS    LAIM  KLLI BRANCJ 1 1  A. 


/.  Cuvieri,  Mantell  (Figs.  69,  84),  both  from  the  zone  of  Mirrnster  cor-ami^ihitnii 
of  Soutlierani ;  in  the  British  Museum,  Nos.  5845,  L22(V,»4. 

I.  Broii'jniiirfi,  Mantell  (Fig.  08),  from  Lewes  or  Brighton  (probahly  zone  of 
Micraster  cor-aiu/niiinw)  ;  in  the  British  Museum,  Xo.   1751. 


I'lO.  S3. — Auterior  view  of  specimen  showu  iu  Fig.  82.      x  }. 


/.  Wehsteri,  Mantell  (Fig.  71),  from  Houth  Street  [=  Southeram],  Lewes 
(pi'obablj  zone  of  Micraster  cor-tcdndimirUtm) ;  in  the  British  Museum,  No.  4759. 

/.  uadalatus,  Mantell  (Plate  LIII,  fig.  o),  from  Southeram,  Lewes  (probably 
zone  of  HiAaster  jylfimts) ;  in  the  British  Museum,  No.  4767. 


IXOCERA.MUS. 


325 


FiCi.  SI. — Innrer'unns  LumarH-i  var.  Ciivieri,  Sow.    Tlie  oriu-inal  of  /.  Cuvii'ri.  Maiiti41, '  Foss.  S.  Downs,'  j).  213, 
pi.  .\xviii,  tii^.  1.     Zone  of  ^Ji'-Tfry^er  coj'-a/(^uintu»  of  Soiitli'Tain.     JJriti.sh   ^lustniin,  Xo.  5845.      x  \. 


Fio.  85.— I/iotf.«iiiKS  Lomarcki,  Park.  Upper  Chalk  (?  zone  of  Holaster  planus),  locality  unknown. 
Museum  of  Practical  Geoloity,  Xo.  21237.  Variety  with  concave  anterior  area.  Right  valve  and 
anterior  view,      x  J. 


32(5 


CRl-rrACEOUS    J.A.MI'JLLIUKAXCIIIA. 


.-^^r 


Fig.  8G.  — Jnoceramus.     A  variety  cnnncctinu^  1.  l,itni<ir<l,i  witli   [.  involutus.     Upper  Chalk,  probably  Kent. 
Sedgwick  Museiiui      Riijlit  valve  displnt'i'il.     Posterior  view,      x  J. 


'7^^- 


FiQ.  87. — .\nteri(ir  view  of  specimen  shown  in  Fig.  86.     Natural  size. 


lAOCEKA.MlS.  327 

I.Jiifiis-,  ]\raiitfll  (  Fiu'.  7<)),  from  tlio  Uiipcr  (Mialk  near  Brighton  ;  in  tlie  Britisli 
Museiini,  No.  -"iSJ-S. 

T.  I'rouguiarti,  Sowerby,  182o  (Fig.  70).  I;Ocality  and  hoi'i/on  unknown  ;  in 
tlie  British  Mnsevnn,  Xo.  -l-o2(j5. 

The  small  specimens  from  the  /one  of  lilii/iiclnnii'llii  C'liriri-l  near  Camljridge, 
figured  by  Etlieridge  as  Iiuiccr((iiinH  jiroltlein<ificiif<,  ari'  in  the  Museum  of  Practical 
Geology  (Xos.  2 1 230-2 1 232). 

Distfihidioii. —  /.  fjiDiiiin-J.-l  ranges  from  the  zone  of  IllDjiirlniiirlhi  Cavieri  to  the 
zone  of  ?\[icraf<tpr  ciir-mujui iiniu} 

Zone  of  Tilij/itchonclhi  I'm-icri -.  St.  Catherine's  Ilill  (Winchester),  the  Isle  of 
Wight,  Cuxton,  Bnrhani,  Dunton  Green,  the  Sussex  coast,  Dover,  Hitchin,  Fovil- 
bourn  near  Cambridge,  the  Yorkshire  coast. 

Zone  of  'rprrJii-iifiilimi  lufn  ;  Hooken  (South  Devon),  the  Isle  of  Wight,  Cuxton, 
Blue  Bell  Hill  (Bui-hani),  Dunton  Green,  Kenlev,  Westerham,  Lewes,  the  Sussex 
coast,  Holborough  near  Rochester,  Dover,  Guilford  Colliery  (Coldred  near  Dover), 
Hitchin,  Koyston,  the  Yorkshire  coast. 

Zone  of  Ifnh(sf('r  j}l(nnis  .-  The  South  Devon  and  Dorset  coasts,  the  Isle 
of  Wight,  Winchester,  Ilomington  (Salisbury),  Cuxton,  Borstal,  Whyteleaf 
(AV;irlinghain),  the  Sussex  coast,  Dover,  Newmarket,  Swaffham  (Norfolk), 
Westacre,  Xarborongh,  the  Yorkshire  coast.     Chalk  Rock  of  Cuckhamsley. 

Zone  of  Micraster  cor-tcstaiVuiariinn  :  The  South  Devon  and  Dorset  coasts,  the 
Isle  of  Wight,  Borstal  Fort,  Borstal  Manor  pit,  Chatham,  Lewes,  the  Sussex  coast, 
Dover,  Wharram  Percy,  the  Yorkshire  coast. 

Zone  of  Minnisfrr  cor-anguinnm  :  The  Dorset  coast,  the  Isle  of  Wight,  Camp 
Hill  (Sali-sbury),  ^licheldever,  Harefield,  Southeiam,  the  Sussex  coast,  St. 
Margaret's,  Thanet,  the  Yoi-kshire  coast. 

Senonian  of  Ifaldon. 


iNOCERAAirs  ixvoi.iTrs,  Soiri'rhi/,  1828.     'i'ext-figs.  88 — 94. 

1828.     Inoceramus  involutus,  .7.  tJi-  C.  Soirerhy.     Miu.  Couch.,  vol.  vi,  p.  16i), 

pi.  dlxxxiii,  figs.  1 — 3. 
1841.  —  —         F.  A.  lii'iiiii-.     ])ie     Versteiu.     d.     uord-deutscli. 

Kreidegeb.,  p.  61. 
1846.  —  —         A.  <rOrhS,jnij.     Pal.    Franc.    Terr.    Crct.,    vol.    iii, 

p.  520,  pi.  ecccxiii,  figs.  1 — 3. 
—  —  Lamakckii,  d'Oihitjiiij.     Ibid.,  p.  518,  pi.  in-cxii. 

1850.  —  INVOLUTUS,  d'Orbigny.     Prodr.  de  Pal.,  vol.  ii,  p.  250. 


'  Some  authors  have  recorded  this  species  \'vi>nt  thezouesof  ifdi-fiiiiillfs  iesliiiJInartiis,  4^cliiiocamax 
quadfatug  and  Bilciiniilelln  iiiiirruiKilii,  but  I  have  not  sufficient  evidence  to  confirm  these  records. 


328  CRETACEOUS   LA.MELLIBRANCHIA. 

1850.      Inoceramus  involutcs,  J.  de  C.  Sowerly,  in  F.  Dixon.     Geol.   Sussex,  p. 

355  (p.  386,  ed.  2),  pi.  xxviii,  fig.  32. 
1854.  —  —J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  169. 

1863.  —  —  A.  V.  Siromhecl:     Zeitscbr.      d.     deutsch.     geol. 

G-esellsfli.,  vol.  xv,  p.  127. 
1871.  —  (VoLvicER.^Mfs)  INVOLUTUS,  F.  StoUczkii.     Pulwout.    ludica, 

Cret.  Faumi    S.  ludia,  vol. 
iii,  pp.  394,  401. 

1875.  —  INVOLUTES,  C.  Df'cocq.     Assoc.     Franc.    Avaiic.    Sci.     (Lille, 

1874),  p.  367. 

1876.  —  —  D.  Bra II III!.     Zeitselir.  f.  d.  gesanimt.  Naturwiss., 

vol.  xlvi.  p.  379. 

1877.  —  —  C.  Svlil'^ter.      PAl8eoutoi,'raplii(.-a,  vul.  xxiv,  ]..  27-_'. 

1878.  —  —  C.  Barrois.     Ann.    Soc.    gi'ul.    du    Nord,    vol.    v, 

p.  475. 
1888.  — •  (VoLviCEUAMUs)  IN'VOLUTUS,  Cr.  .W/(7/(>/-.     Jalu'b.  d.  k.  preus.s. 

geol.  Landesanst.  fiir  1887,  p.  411, 
pi.  xvi,  figs.  3,  4. 
—  —  ixvoLUTUs,    A.    Pemii.     Hist.    Terr.    Craie    S.E.    du    Bassiii 

Auglo-Pai'isien,  p.  157. 

1901.  —  —  F.  Sliinii.     Jalirb.  d.  k.  preuss.  geol.  Landesanst. 

fiir  1900,  vol.  xxi,  p.  91,  pi.  ix,  fig.  4. 

1902.  —  —  A.  Wolleiiianii.     Liineburg.  Kreide   (Abliaudl.   d. 

k.    prtuss.    geol.    Landesanst. 
N.F.,    37),  p.  68,  pi.  i,  fi;,'.  4; 
pi.  ii,  figs.  7,  8. 
1906.  —  —  G.  Smolei'igM.     Bull.  Intern.  Acad.  Sci.  Cracovie, 

p.  721. 

1909.  —  —  J.  Nnwal:     Ibid..  \<.  874,  pi.  xlvi,  figs.  4,  5. 

1910.  —  —  J.  Bvhin.     CVntralbl.  fiir  Min.,  etc.,  p.  741. 

DescrlpHon. — Bliell  very  iiu'(|uivalvr  and  wvy  iiiequilatei-al.  Riglit  valve  oval 
or  semi-oval  in  outline  ;  usually  slig'litly  coiive.x.  I)ut  .sometimes  either  more  convex 
or  nearly  fiat,  with  the  uuirginal  part  in  old  specimens  forming  an  obtuse  angle 
with  the  earlier  part,  liength  greater  than  height.  Anterior  and  ventral  margins 
rdunded  ;  posterior  margin  forming  usually  an  obtuse  angle  l)ut  sometimes  nearly 
a  right  angle  with  the  hinge.  Umbo  usually  incdnspicuons,  at  or  near  the 
anterior  end  of  the  hinge-line.  Hinge-line  e(iuals  about  thrt'c-cpiarters  of  the 
length  of  the  valve.  Postero-dorsal  nuirginal  part  convex  near  the  hinge  and 
separated  by  a  sharp  furrow  from  the  remaimlei'  of  the  \alve.  Ornamentation 
consists  of  strong,  somewhat  irregular  concentric  folds,  with  an  un.symmetrical 
curvature;  the  folds  are  sej^arated  l)y  broad,  concave  interspaces.  In  casts  of  this 
valve,  ami  sometimes  in  the  shell  itself,  radial  markings  ai'e  seen  in  the  concave 
interspaces. 

Left  valve   much   lai-ger   than    the   right,    inflated,   more   or  less   considerably 

\ 


IXUCERAMUS. 


32'.> 


Fig.  88. — Inuccramits  involatiis,  Sow.     Upper  Chalk,  locality  imknciHn.     The  tyn'.     British   Museum,  Xo. 

43268.     Left  valve.     Natural  size. 


Via.  H9.  —  hiortr<imiit  iiivolulua.  Hkw.     The  ori^'inal  of  the  .■^poeiiiieil  fi.,'Uiivl  iu   I)i.\on'.s  '  Ueol.   Sussex."  pi. 
.vxviii.  fi;;.  -.i'.     Upper  Chalk,  Charinj,'.     Flint  east.     British  Museuui,  Xo.  LS.J.     Natunil  size. 


:3:30 


CRETACEOUS   L.UIELLIFiRAXCHIA. 


J 


J^'l 


Fiii.  'M.  —  Inoccriiiiius  involntus.Sow.     Upper  Chalk,  probably  Kent.     British  Museum,  No.  Li'Jl".     Posterior 
view.     Uinboiial  part  of  left  valve  missing.     Natural  size. 


<  r 


f 


\ 


KiG.  91.— Anteririr  view  of  specimen  shown  in  Fig.  90.     Natural  size. 


IXOCERAMUS. 


spiral  ;    witli    a    very   lar^'c  iiiubo    near    the    anterior    end,    ciirveil    iiiwai-ils  ami 
forwards.     Surface  nearly  sinootli,  except  for  the  presence  of  n'rowth-lines. 

Tlie  liinge  (Fig.  94)  curves  at  either  end  ;  it  is  thinnest  near  the  umln)  and 
becomes  thicker  towards  the  posterior  end.  The  ligament-pits  are  deep,  almost 
square,  but  sometimes  oblong,  and  increase  in  height  from  the  umbo  posteriorly. 


1^. 


% 


/ 


I 


Fio.  92.— Ki^ht  viilve  and  part  of  left  valve  of  specimen  shown  in  Figs.  90,  91. 

AfUnUies. — I.  inrolufns  i&  the  type  of  the  genus  or  sub-genus  Volcicem))nis  of 
Stoliczka.  In  general  appearance  this  differs  considerably  from  other  species  of 
Inoceramus,  so  that  its  separation  as  a  distinct  genus  or  sub-genus  seems  at  first 
sight  (juite  justifiable  ;  but  the  study  of  a  large  number  of  specimens  of  /.  iiiroliitiis 
and  I.  Lamarcki  shows  that  these  two  species  arc  very  closely  allied,  and  that  the 
former  has  almost  certainly  descended  from  the  latter.  Such  being  the  case  it 
follows  that  these  two  species  are  more  nearly   related  to  one  another  than  aiv 


332 


t'KKTACKOU.S    J.A.MElJ.IHKAXClllA. 


several  species  wliicli  are  jilaecil  liy  all  writers  in  the  genus  Iiioceramns.     In  this 
respect  Volriceraman  is  exactly  coniparalile  with  Jcfinoceramitu  (p.  268). 

A  fairly  complete  passage  can  l)e  traceil  from   T.  Lamairli  tn   [.  inruliifi(.<i.     In 
some  forms  of  /.  Lumarcld  the  valves  l)econie  more  uiuMjual  than   usual,  the  left 


Fill.   9;J. — hioceramns    inmhitiis.   Sow.      Upp:M-  Chalk,  locality  unkuowu.      British  JIusoum,  Xo.  L21005. 

Anloiior  view  of  left  valve.       x    J. 

valve  being  relatively  larger  and  witli  less  distinct  folds,  and  the  right  relatively 
less  convex  and  its  anterior  area  slightly  concave  (Fig.  85).  These  are  connected 
with  some  varieties  of  /.  iiirohdiis  by  intermediate  foi'ms  (Figs.  8(3,  87)  in  which 
the  left  valve  possesses  neai'ly  all  the  characters  of  /.  iiirulntiis  l)ut  is  less  curved 
and  possesses  a  concave  anterior  area,  whilst  on  the  right  valve  the  folds  are 
almost  as  ]irominent  as  in  I.  iurolutus,  but  the  flattened  or  concave  anterior  area 


TNOCERAMTTS. 


333 


and  a  relatively  short  hinge  are  still  retained,  and  the  right  valve  is  still  convex 
and  has  a  concave  anterior  area.  A  variety  of  /.  vivolufiifi  links  snch  intermediate 
forms  with  typical  examples  of  involidus ;  in  that  variety  the  right  valve  is  rather 
more  convex  than  in  typicnl  forms,  the  left  valve  is  not  so  distinctly  spiral,  some 
trace  of  the  anterior  flattened  or  concave  area  is  still  retained,  and  the  hinge-line 
is  rather  shorter  relativelv. 


-- «;jv:^pxEmq 


Fig.  91. — /iiorcramus  into(«(ns,  Sow.    Upper  figure  :  Zone  of  iVic)"as(error-niigHiiir(«i.  Gravesond.     Sedgwick 
Museum,  Cambridge.     Kiglit  valve  witli  marginal  growth  round  the  hinge,      x    J. 
Lower  figure  :  Hinge  of  right  valve  ;   Upper  Chalk,  Norfolk.     Norwich  Museum,  No.  3355.     The  anterior 
part  of  the  hinge  is  partly  concealed  by  the  marginal  growth  of  the  shell,      x  |. 

/.  nmhnnatns,  Meek  and  Hayden,'  fiom  Fort  Benton,  Missouri,  is,  as  stated  by 
Meek,  very  closely  allied  to,  and  perhaps  identical  witii,  /.  incolidHS.  Another 
related  form  is  /.  exogyroides.  Meek  and  Hayden.'^     Both  are  regarded  as  synonyms 

1  'Invert.  Cret.  and  Tert.  Foss.  U.  Missouri'  (1876),  ]>.  44,  pi.  iii,  fi<.'.  1  :  jjI.  iv.  tigs.  1,  2. 

2  Ibid.,  p.  46,  pi.  V,  fig.  3. 

44 


334  CRETACEOUS    LAME] .LTRTJANCHIA. 

of  I.  involutiis  by  Barrois.  /.  Koeneni,  Miiller,'  is  probably  a  variety  of 
/.  involntus  in  which  the  riijht  valve  is  more  convex  and  its  umbo  more  prominent 
than  usual. 

The  right  valve  of  the  specimen  figured  by  d'Orbigny  (184G,  pi.  ccccxii, 
figs.  1,  2)  as  I.  Lamarclci  is  an  example  of  /.  involntus;  but  the  left  valve  (fig.  3), 
if  it  belongs  to  the  same  individual,  is  probably  incorrectly  drawn. 

Remarks. — Examples  of  this  species  often  reach  a  large  size,  and  in  such  cases 
the  hinge  (Fig.  94)  may  attain  a  considerable  thickness,  but  portions  of  it  are 
not  often  found  separately.  In  old  specimens  the  marginal  part  of  the  right 
valve  grows  obliquely  or  almost  at  right  angles  to  the  earlier  part,  and  the  folds 
become  indistinct  or  disappear  altogether;  and  in  the  right  valve  this  marginal 
growth  sometimes  occurs  along  the  hinge,  owing  no  doubt  to  the  increase  in  size  of 
the  left  valve  in  which  it  then  fits  like  an  operculum  (Fig.  94).  The  hnigtli  varies 
in  proportion  to  the  height,  so  that  in  some  forms  the  right  valve  becomes  nearly 
circular. 

Tijpes. — The  type  (Fig.  88)  is  in  the  British  Museum,  No.  432G8  ;  its  locality  is 
unknown.  The  specimen  figured  in  Dixon's  '  Geology  of  Sussex  '  (Fig.  89)  is  also 
in  the  British  Museum,  No.  L83  ;  it  is  a  flint  cast  and  came  from  the  Upper  Chalk 
of  Charing. 

Distribution. — /.  involntus  is  found  in  the  zone  of  Micrastcr  cor-testudinarinni 
and  the  lower  part  of  the  zone  of  M.  ror-angninuui,  being  particularly  common  at 
the  latter  horizon." 

Zone  of  M.  cor-testudinarium :  Chatham,  Dover,  and  Seaford,  Sussex. 

Zone  of  M.  cor-anguinum :  Winchester,  Quidhampton,  Mapledurham,  Thanet, 
St.  Margaret's,  Guilford  Colliery  (Coldred  near  Dover),  the  Sussex  coast,  Lewes, 
Haling  pit  (South  Croydon),  Strood,  New  Brompton  (Chatham),  Gravesend, 
Harefield  near  Rickmansworth,  Bury  St.  Edmunds,  Saham  Toney,  Thetford, 
Brancaster,  and  other  places  in  Norfolk.  Between  the  zones  of  M.  cor- 
testudinarium  and  M.  cor-anguinum  near  Beverley,  Yorkshire.  Senonian  of 
Haldon. 

Inoceramus  cokdiformis,  Sowerby,  1823.    Plate  LIII,  fig.  8.    Plate  LIV,  figs.  2—4. 

1823.     Inoceramus  cokdiformis,  J.  d<:  C.  Sowerby.     Miu.  Couch.,  vol.  v,  p.  Gl. 

pi.  ccccxl. 
183G.  —  —  A.  Goldfu.<'s.      Petref.  Germ.,   toI.  ii,  p.  113, 

pi.  ex,  fig.  6b  (not  6a). 


'  Jahrb.  d.  k.  preuss.  geol.  Landesanst.'  fiir  1887  (1888),  p.  412,  pi.  xvii,  fig.  1. 
2  This  species  has  been  recorded  by  Griffith  and  Brydone  from  the   Vintacrinus  baud  of   the 
Marsupites  zone  of  Ropley,  Hampshire  :  and  by  Barrois  fnmi  the  zone  of  Actinocamax  quadratus  of 
Newhaven. 


TN0CERAMU8.  335 

1854.     Inoceramus  CORDIFORMIS, /.  Morris.     Cat.  Brit.  Foss.,  wl.  2,  p.  109. 

1897.  —  R.  Leonhard.      PalieontograpluLa,  vol.  xliv,  p.  48. 

1898.  Haenleini,  G.  Midler.     Mollusk.  Uiitersen.  v.  Brauuschweig 

u.    Ilsede   (Abhaudl.  d.   k.   preuss. 
geol.  Landesanst.,  n.f.,  25),  p.  41, 
pi.  V,  fifj.  7 ;  pi.  vi,  figs.  1,  2. 
?1911.  —  coViUiYoiiuis,  W.  Ro(jala.     Bvdl.  Iiiternat.  Acad.  Sci.  Ciacovie, 

p.  170,  pi.  iv,  fig.  2. 

Non  1904.  —  _  0.  Airaghi.     Boll.  Soc.  geol.  Italiana,  vol.  .xxiii, 

p.  189,  pi.  iv,  figs.  6—9. 

Descriptiou. — Shell  inflated,  eciuivalve,  very  inequilateral,  rouucled.  Anterior 
margin  more  or  less  nearly  straight  or  undulating,  l)ut  rounded  in  large  specimens. 
Venti'al  and  posterior  margins  more  or  less  sinuous.  Anterior  part  of  valves 
more  or  less  flattened  and  often  nearly  perpendicular  to  the  plane  between  the 
valves.  Postero-dorsal  part  of  valves  much  compressed  and  usually  wing-like. 
Hinge  equal  to  more  than  half  the  height  of  the  shell.  Umbones  terminal,  large, 
prominent,  curved  inwards  and  forwards.  A  broad,  shallow  sulcus  extends  from 
behind  the  uinl)o  to  the  postero-ventral  extremity  and  separates  two  broad, 
rounded  ridges.  A  similar  sulcus  nuiy  extend  from  the  front  of  the  uml)o  to  the 
opposite  ventral  margin. 

Ornamentation  consists  of  broad,  rounded,  concentric  folds,  which  bend 
upwards  where  they  cross  the  two  radial  sulci.  The  folds  become  less  distinct 
on  the  anterior  and  postero-dorsal  parts  than  on  the  sides  of  the  shell.  Numerous 
close-set  growth-lines  are  present. 

Affinities. —  /.  Haenleini,  Miiller,'  from  the  lower  part  of  the  Lower  Senonian  of 
Brunswick  and  Ilsede,  seems  to  be  hardly  distinct  from  /.  cordiformis.  The 
smaller  English  specimens  agree  very  closely  with  one  of  the  examjiles  figured  liy 
Midler  (pi.  v,  fig.  7). 

/.  cordiformis  resembles  some  of  the  more  convex  forms  of  /.  Lumarcki, 
Parkinson,  from  which  it  is  distinguished  by  the  ecjual  size  of  the  valves  and  the 
presence  of  radial  sulci.  The  specimen,  figured  (I'l.  LIV,  fig.  1),  connects  this 
species  with  I.  Lamarchi. 

Remarks. — Goldfuss'  fig.  (ii  is  a  copy  of  Sowerby's  figure  ;  his  fig.  (i'(  is  the 
type  of  /.  .'^a.eniiiriiii,  Petrascheck. 

Ti/pe. — In  the  British  Museum,  No.  43277,  from  the  Upper  Chalk  (zone  of 
Micraster  cor-anguinum)  of  Gravesend  (PI.  LIII,  fig.  8). 

Distribution. — Zone  of  Micraster  cor-testudinariuni  of  C.'lanfield  (Hampshire), 
and  Wharram  Percy  (Yorkshire).  Zone  of  MicraMer  cor-anguinum  of  Gravesend, 
Micheldever,  and  Portou.       Uintacrinus  band  of  Salisbury.     Senonian  of  Haldon. 

'  'Mollusk.  Uutersen.  v.  Biauuschweig  u.  Ilsede'  (1898),  p.  41,  pi.  v,  tig.  7;  pi.  vi,  tig.s.  1,  2. 


336  CRETACEOUS    LAMELLIBRANCHIA. 


Inoceeamus  costellatus,  sp.  nov.     Plate  LIV,  figs.  5 — 7. 

1897.     Inoceeamus,  sp.,  H.  Woods.     Quart.  Journ.    Geol.    Soc,   vol.  liii,    p.  381, 

pi.  xxvii,  figs.  14 — 17. 

Description. — Shell  small,  vei\y  inequilateral,  rather  hig-lier  than  long,  of 
moderate  convexity — the  greatest  convexity  being  between  the  umbones  and  the 
postero-ventral  extremity.  Umbones  terminal.  Hinge  equal  to  about  three- 
quarters  of  the  length  of  the  shell,  and  forming  more  than  a  right  angle  with  the 
anterior  margin.  Anterior  margin  moderately  convex,  ventral  margin  very 
convex,  posterior  margin  slightly  convex. 

Right  valve  with  a  small,  pointed,  slightly  curved  umbo.  Posterior  and  postero- 
dorsal  parts  of  the  valve  flattened  A  small,  flattened  antcro-dorsal  area  is  nearly 
perpendicular  to  the  plane  of  the  valves. 

Left  valve  more  convex  than  the  right ;  postero-dorsal  part  compressed,  but 
not  forming  a  definite  ear.  Umbo  narrow,  pointed,  curved  inwards,  larger  and 
more  prominent  than  tlie  umbo  of  the  right  valve.  Antero-dorsal  area  larger 
than  on  the  right  valve. 

Concentric  ribs  narrow,  sharp,  usually  widely  separated;  interspaces  broad 
and  shallow.  The  curvature  of  the  ribs  is  very  unsymmctrical ;  the  ventral  part 
is  very  convex,  the  posterior  part  only  slightly  convex. 

Bemarlis. — This  species  is  fairly  common  in  the  Chalk  Rock.  All  the  speci- 
mens seen  are  casts.  Some  examples,  Avhich  appear  to  be  a  variety  of  this  species, 
have  small  ribs  of  uniform  size. 

Affinities. — This  species  appears  to  be  related  to  some  foi-ms  of  /.  Lainarrl-i, 
Parkinson,  but  the  left  umbo  is  narrower,  more  pointed,  and  less  curved  ;  the  line 
of  gTeatest  convexity  is  more  oblique  to  the  hinge-line,  and  the  posterior  and 
postero-dorsal  parts  of  the  valves  are  more  conijiressed.' 

Type. — From  the  Chalk  Rock  of  Cuckhamsley,  in  the  Sedgwick  Museum, 
Cambridge. 

Distribution. — Chalk  Rock  of  Dover,  Guilford  Colliery  (Coldred  near  Dover), 
the  Sussex  Coast,  south-east  of  Calstone  Willington,  Cuckhamsle}',  Blount's  Farm 
near  Marlow,  Luton,  Wallington  near  Baldock,  ]3arley  near  Royston,  and 
Underwood  Hall  near  Dullingham.  Zone  of  HoJastcr  jilnnns  of  South  Devon,  the 
Dorset  Coast,  the  Isle  of  Wight,  Lichfield  (Hants),  Winchester,  etc." 

'  Corapaiv  also  /.  iinJulaliis,  Eogala,  •  Bull.  luteruat.  Acad.  Sci.  Cracovie'  (1911),  p.  171,  pi.  iv, 
fig.  7,  and  /.  Frecld,  Audert,  '  Inooeraineu  d.  Kreibitz-Zittauer  Sand  stein  geb.'  (1911),  p.  51,  pi.  i, 
fig.  8. 

2  Recoi'ded  iiy  Rowe  froui  tlic  zones  of  Terebraluliiia  lata  and  Micraster  cor-anguinum  of  Dover. 


IN0(1KRAI\IUS. 


337 


Inoceramus  digitatus,  Sowerby,  1829.     Text-fig.  05. 

1829.     Inockramtts  digitatus,  J.   cle  C.    Sowerbtj.     Miu.  Conch.,  vol.  vi,  p.  215, 

pi.  dciv,  fig.  2. 
1854.  —  —  /.  Mf,rn>'.     Cat.  Brit.  Foss  ,  e.l.  2,  p.  169. 

?  1875.  —  —  C.   Di'cocq.     Assoc.     Fran9.    Avanc.    Sci.    (Lille, 

1874),  p.  368. 

Remarlis.- — This    species   attains    a   large    size,    but  is    known  only  Ijy  small 


Fio.  95. — Inoceramus  di'jitnlus,  Sow.      The   typt-.      Fi-oin  tlie  Drift  (JerivuU   from  tlie   Ciialk).      Uritish 

MuseKiii,  No.  43273.      x  J. 


portions  of  the  shell  of  which  the  exact  horizon  cannot  be  determined.  The 
ornamentation  consists  of  broad,  rounded,  radial  folds,  which  diverge  very 
gradually  and  are  separated  by  broad  rounded  interspaces.  Small  concentric 
ribs  occur,  and  at  distant  intervals,  broad,  gentle,  concentric  folds  can  be  traced. 
The  form  referred   to   /.  (Jiijiiatus  by  Schli'iter  differs  from  that  species  in  having 


/ 


338  CRETACEOUS    LAMHLI/IHKAXCHIA. 

diverging  and  distinctly  curved  ribs.  7.  di(/itafiis  appears  to  be  closelj'  allied  to 
/.  subcardissoide>^-,  Sclili'itcr. 

Ti/))f. — From  the  Drift  (derived  from  the  Chalk)  ;  locality  unknown.  In  the 
British  Museum,  No.  43,273. 

Distrihdion. — No  undoubted  specimens  obtained  directly  from  the  Chalk  have 
been  seen. 


Inoceramus  PiNNiFORMis,  WiUetf,  1871.     Text-fig.  96. 

1871.     Inocekamus  pinnifoemis,  II.  Willett.     Cat.  Giet.   Foss.,   Brighton    Mus., 

p.  40,  uo.  342. 

Description. — Shell  very  large,  much  higher  than  long,  of  moderate  convexity, 
Avith  a  posterior  wing-like  part. 

Ornamentation  consists  of  broad,  strong,  widely  separated  concentric  folds 
which  have  a  nearly  symmetrical  curvature;  the  ventral  slopes  of  the  folds  are 
rather  steeper  than  the  dorsal ;  in  the  interspaces  are  small  (sometimes  indistinct) 
concentric  folds,  which  give  a  moi'e  or  less  marked  tuberculate  character  to  the 
radial  ribs.  The  latter  are  rounded,  rather  numerous,  sometimes  partly  or  com- 
pletely divided  by  a  median  furrow,  and  are  continued  on  to  the  dorsal  surfaces 
of  the  strong  concentric  folds,  but  are  absent  or  indistinct  on  the  ventral  surfaces. 

Bfrnarks. — A  portion  of  a  large  Inoceramns  named  7.  pianifurmiti  liy  Willett 
resembles  7.  sulicardissoiiles,  Schliiter,^  but  differs  from  that  species  Ijy  tlie  more 
numerous  radial  ribs  and  the  absence  of  a  broad  furrow  extending  from  the  umbo 
in  a  postero-ventral  direction. 

Ti/pi'. — In  the  Brighton  Museum. 

DistribiUioit. — Upper  Chalk  (zone  of  Ai'tiiiocn imrr  qHudrnfiis)  of  i'.rigliton,  and 
three  miles  east  of  Sled  mere,  Voi'kshire. 

•  '  Palaeoutograiiliica,'  vol.  x\lv  (1877).  p.  271,  jil.  .xx.wii  ;  Baimi.s.  '  Auu.  Soc.  gvol.  Nord.,' 
vol.  V  (1878),  p.  474-;  Wollt'inami,  '  Luncbnr^r.  Kreide'  (1902),  p.  70;  Wegiinr,  '  Zeitschr.  d. 
deutsuh.  Kt'ol.  GivscllsL-h.,"  vol.  Ivii  (liMl.")).  p.  169;  I.  (t'oxho/c/i',  Dccocq,  'Assoc.  Franc.  Avaiic  Sci.,' 
1874  (1876),  p.  371. 


TxorKi^AMrs. 


339 


/i 


■  M 


"V 


*<^'i 


i 


'■Ji-' 


I 


i^^m 


/I  I 


f 


Fiu.  91). — /iioi-eraniiis   pinni/nimis,  Willint.       I'lipiT   Clmlk    (zone   of   Arlinocamaz  i/uaJratHs),  Brighton. 
Brighton  Museum,  Xo.  :{42.     Portion  o£  right  valve,      x  J. 


340 


CRETACEOUS   LAMELLTBRANCHIA. 


Inoceramus  corrugatus,  sp.  iiov.     Text-fig.  07. 

Bemarlc!^. — This  species  is  at  present  known  only  by  a  small  portion  of  one 
valve.  It  is  of  the  same  general  type  as  /.  iVKjitatm,  Sowerby,  I.  imviiforinis, 
Willett,  and  /.  xtihrard'n^soldes,  Schliiter,  Init  owing  to  the  presence  of  broad, 
strong  radial   folds  tlic  radial  ribs  are  arranged  in  groups  of  four  or  five.      The 


Fin    97._Jnnccra)iiws   enrnigatus,   sp.  nov.     Upper  Chalk,  Wouldham   Cement  Quarry,   Grays.     Britisli 
Museuiii,  No.  Ti22.")28  (discovered  and  presented  )iy  Col.  C.  E.  Sliepherd).     Natural  size. 

concentric  folds  are  strong  and  have  a  steep  ventral,  and  a  gentle  dorsal  slope. 
The  growth-lines  are  distinct  and  regular.  /.  cornujafn.-;  and  the  other  species 
mentioned  may  be  compared  with  /.  lezemiemis,  Decocq,'  which  is  of  the  same 
type  as  I.  Lamarcki  but  possesses  two  radial  folds  due  to  the  presence  of  a  medial 

sulcus. 

Distribution.— JJ^^ev   Chalk,  Wouldham   Cement   Company's   Quarry,   Grays, 

Essex. 

I  Barrois,  '  Ann.  Soc.  geol.  ilu  Nord,"  vol.  vi  (1870),  p.  465,  pi.  5,  figs.  1,  2. 


palcxontoovapbical  Socict\>,  1012. 


A     MONOGRAPH 


CRETACEOUS    LAMELLIBRANCHIA 


ENGLAND, 


HENRY  AVOODS,  M.A. 

UNIVEKSITY    LECTURER    IN    PALa:OZOOLOOT,    CAMBRIDGE. 


VOL.  TI.     PART  IX. 

OSTREID^,    RADIOLITID.E,    ADDITIONS,    DISTRI15UTI0N, 
BIliLIOGRAPHY,    INDEX. 

Pages  341—473;   Plates  LV— LXII. 


LONDON: 
PRINTED     FOR     THE     PAL^ONTOGRA  PHIC  AL     SOCIETY. 

1913. 


PRINTED    BT    ADI.ARD    AND    SON,    LONDON    AND    DOKKINQ. 


OSTREID^.  341 

i^ami///— OSTREID^,  Lamarck. 
[Omitted  from  Vol.  I,  p.  223.] 

The  great  difficulties  in  the  systematic  study  of  the  Ostreidaj  have  been 
felt  by  nearly  all  writers,^  and  are  due  mainly  to  the  extraordinary  variation 
in.  the  form  of  the  shell.  This  variation  has  been  brought  about  by  changes  in  the 
physical  conditions  of  habitat,  and  particularly  by  differences  in  the  character  of  the 
surface  to  which  the  left  valve  is  fixed ;  it  is  found  that  the  mode  of  growth  and 
ultimate  shape  of  the  shell  are  determined  mainly  by  the  size,  shape,  and  position 
of  the  attached  surface,  so  that  commonly  any  one  species  shows  an  amazing  variety 
of  forms  which  can,  however,  be  linked  together  by  large  series  of  specimens.  A 
further  difficulty  in  the  systematic  study  of  oysters  is  due  to  the  fact  that  the  shell 
usually  possesses  little  or  no  ornamentation. 

Various  generic  or  sub-generic  divisions  have  been  proposed  for  the  Ostreidse, 
e.  g.  Ostrea,  Lopha  (  =  Aledri/onia),  Arctostrea,  Exogyra,  Amphidonta,  Grijphxa, 
Pycnodonta,  Gryphseostrea ;  but  it  appears  to  me  that  the  phylogenetic  relationship 
of  the  species  of  oysters  is  more  complex  than  is  represented  by  these  divisions, 
and  that  a  natural  grouping  can  only  be  established  when  more  is  known  of  the 
evolution  of  the  species.  The  forms  with  radial  folds  have  usually  been  grouped 
together  under  the  name  Alectryonia ;  but  there  can  be  no  doubt  that  such  folds 
have  originated  independently  in  more  than  one  line  of  descent,  and  their  presence 
does  not  necessarily  indicate  close  relationship.  Thus,  for  example,  Ostrea  semi- 
2)la7ia,  which  has  been  commonly  referred  to  Alectryonia,  appears  to  be  more  closely 
allied  to  Ostrea  vesicidaris  than  to  any  species  of  Alectryonia.  The  Cretaceous 
forms  which  have  been  referred  to  Gryphsea  clearly  owe  their  grypheate  character 
to  the  small  size  of  the  attached  surface,*  and  can  be  traced  into  forms  having  the 
characters  of  Ostrea.  In  studying  the  Upper  Cretaceous  oysters  of  Tunis,  Peron^ 
has  already  noticed  that  some  individuals  of  a  species  may  present  the  characters 
of  Ostrea,  whilst  others  are  exogyriform  or  grypheate.  In  the  Chalk  of  England 
Ostrea  semiplana  is  usually  ostreiform,  but  occasionally,  when  the  attached  surface 
is  behind  the  umbo,  the  shell  is  at  first  exogyriform,  but  afterwards  becomes 
ostreiform. 

1  See,  for  example,  the  remarks  of  Hill  and  Vaughan,  "  Lower  Cretaceous  Gryphaeas  of  the  Texas 
Region"  ('Bull.  U.S.  Geol.  Survey,'  No.  151,  1898),  p.  24;  and  Perou,  "  Descript.  Brach.,  etc, 
Terr.  Cret.  Tunisie  "  (1890—91),  pp.  105—109. 

-  See  R.  T.  Jackson,  "  Phylogeuy  of  the  Pelecypoda.  The  Aviculidae  and  their  Allies"  ('Mem. 
Boston  Soc.  Nat.  Hist.,'  vol.  iv,  1890),  p.  317  i]  H.  Douvillc,  'Bull.  Soc.  gt'ol.  France,'  ser.  4,  vol.  x 
(1910),  pp.  635,  642. 

'  Op  cit.,  p.  107. 

45 


342  CRETACEOUS   LAMELLIBRANCHIA. 

In  this  work  Exogyra  is  retained  as  a  genus  since  the  species  dealt  with  seem  to 
be  genetically  related,  but  it  is  probable  that  the  exogyriform  type  has  originated 
independently  in  some  earlier  deiDOsits.  It  is  even  possible  that  a  few  species 
referred  to  Ostrea  may  have  arisen  from  an  exogyriform  type  by  the  increase  in  the 
size  of  the  attached  surface,  and  the  gradual  loss  of  the  spiral  character  of  the 
umbo. 

In  the  Ostreidpe,  perhaps  even  more  than  in  the  case  of  hioceramns,  the  number 
of  figures  which  can  be  given  is  altogether  insufficient  to  convey  an  adequate  idea 
of  the  great  variability  of  the  species.  It  is  only  by  the  study  of  very  extensive 
collections  of  specimens  that  one  can  hope  to  arrive  at  satisfactory  conclusions. 

Genus — Ostkea,  Linnseus,  1758. 
('  Sjst.  Nat.,'  eJ.  10,  p.  696.) 

Ostrea  diluviana,  L.     Text-figures  98-138. 

1767.  Ostrea  diluviana,  Linnxtis.     Syst.  Nat.,  ed.  12,  p.  1148. 

1768.  G.   W.   Knorr  and  J.  E.  M.   Walch.     Eecueil.     Mon.  Catastr.  Petrificat., 

vol.  ii,  ji.  123,  pi.  D  ii,  figs.  5,  6. 
1779.     "  Getphite,"  B.  Faujas-St.-Fond.     Hist.  nat.  Mont.  St.  Pierre  de  Maes- 

tricht,  p.  151,  pi.  xxiv,  figs.  1,  2. 
1806.     OsTEEA  PECTiNATA,  Lumarck.     Ann.  du  Museum,  vol.  viii,  j).  165  ;  vol.  xiv, 

1809,  pi.  xxiii,  f.  1. 

—  —       CAEINATA,  LamarcJc.     Ibid.,  vol.  viii,  p.  166. 

1811.  —        FRONs,  J.  Parkinson.     Organic  Eemains,  vol.  iii,  p.  217,  pi.  xv, 

fig.  4. 
1813.     OsTEACiTES  PLiCATissiMtrs,  E.  T.  V.  ScJilotheim.    In  Leonbard's  Taschenb. 

fiir  Miu.,  vol.  vii,  p.  112. 
1819.     Ostrea  coltjbrina,  Lamarch.     Anini.    sans   Vert.,    vol.  vi,  j).   216    {non 

Goldfuss). 

—  —       CAEINATA,  Lamarch.     Ibid.,  p.  216. 

—  —       DILUVIANA,  Lamarck.     Ibid.,  p.  214. 

1821.  OsTEAciTES  DiLuviANUs,  G.  WaMenberg.     Petrific.  Tellur.  Suecanse,  p.  58. 

1822.  OaiiBEA  CAEINATA,  /.  Sowerly.     Min.  Conch.,  vol.  iv,  p.  89,  pi.  ccclxv. 

—  —  —  G.  B.  Sotverhij.     Genera  Eecent  and  Foss.  Shells,  No. 

vi,  fig.  1. 

—  —       8EREATA,   G.   Ciiviev   and  A.  Brongniart.     In  Cuvier's  Ossemens 

Fobs.,  vol.  ii,  pt.  2,  pp.  251,  599,  pi.  iii,  fig.  10. 

—  —       CAEINATA,   Cuvier  and   Brongniart.     Ibid.,   pp.  320,   599,   pi.   iii, 

fig.  11. 
'  1824.  —       MACEOPTEEA,  J.  de  C.  Sowerly.      Miu.  Conch.,  vol.  v,  p.  105,  pi. 

cccclxviii,  figs.  2,  3. 


OSTREA.  343 

1827.     OsTREA  DiLTJviANA,  S.  Nilssoii.     Petrific.  Suecana,  p.  32,  pi.  vi,  figs.  1,  2. 

—  —  —  O.   P.   Deshayes.        Hist.    nat.   Vers   et   MoUusques 

(Encycl.  method.),  vol.  iv,  pi. 
clxxxvii,  figs.  1,  2  ;  pi.  clxxxviii, 
figs.  1,2. 

1832.  —       CAEiNATA,   Deshayes.     Ibid.,  vol.  ii,  p.  301  ;   Planches,    vol.    iv, 

pi.  clxxxvii,  figs.  3 — 5. 

1833.  —  —       A.   Goldftiss.     Petref.   Germ.,  vol.  ii,    p.  9,   pi.    Ixxiv, 

fig.  6. 

—  —       PECTiNATA,  Goldfuss.     Ibid.,  p.  9,  pi.  Ixxiv,  fig.  7. 

—  —       PRiONOTA,  Goldfuss.     Ibid.,  p.  10,  pl.  Ixsiv,  fig.  8. 

—  —      SEREATA,  Goldfuss.     Ibid.,  p.  10,  pl.  Ixxiv,  fig.  9. 

—  —       niLUviANA,  Goldfuss.     Ibid.,  p.  11,  pl.  Ixxv,  fig.  4. 

1835.  Alectryonia  Defrancii,  G.  Fischer  de  Waldheim.    Bull.  Soc.  Imper.  Nat. 

Moscou,  vol.  viii,  p.  113,  pl.  iii. 
?    —  —  Ferussaci,  Fischer  de  Waldheim.     Ibid.,  p.  Ill,  pl.  iv. 

1836.  OsTREA  eetusa,  /.  de  C.  Soiverhy.     Trans.  Geol.  Soc,  ser.  2,  vol.  iv,  pji. 

338,  361,  pl.  xiv,  fig.  4. 

1837.  —       DiLuviANA,  W.  Hisinger.     Lethaea  Suecica,  p.  49,  pl.  xiv,  fig.  5. 

—  —  —  F.  Dujardin.      Mem.   Soc.   geol.    de   Prance,    vol.    ii, 

p.  230. 
?    —  —       GREGARiA,  F.  C.  L.  Koch  and   W.  Blinker.     Beitr.  nord-deutsch. 

Oolithgebild.,  p.  50, 
pl.  vi,  fig.  2. 
1839.  —       RECTANGULARis,  F.  A.  Bonier.     Verstein.  nord-deutsch.  Oolithen- 

geb.,  Nachtrag,  p.  24,  pl.  xviii, 
fig.  15. 

—  —       DILUVIANA?,  H.  B.  Geinitz.     Char.  d.  Schicht.  u.  Petref. des  silchs. 

Ereidegeb.,  pt.  1,  p.  19. 
1841.         —       MACROPTERA,   F.   A.    Bonier.      Die    Verstein.    d.    nord-deutsch. 

Kreidegeb.,  p.  45. 

—  —       CARiNATA,  Bonier.     Ibid.,  p.  45. 

—  —       SERRATA,  Bonier.     Ibid.,  p.  45. 

1845.  —       CARINATA  ET  0.  PRIONOTA,  E.  Forhes.     Quart.  Journ.  Geol.  Soc, 

vol.  i,  p.  250. 
1845-6.      —       DILUVIANA,  H.  B.  Geinitz.     Grundr.  d.  Verstein.,  p.  478. 

1846.  —       CARINATA,  A.  E.  Beuss.     Die  Verstein.  der  biihm.  Kreideformat., 

pt.  2,  p.  38. 

—  —       DILUVIANA,  Beuss.     Ibid.,  p.  38,  pl.  xxx,  figs.  16,  17  ;  pl.  xli,  fig.  1 ; 

pl.  xiv,  fig.  1.  • 

—  —       CARINATA,  A.  Leymerie.     Statist,  geol.  min.  de  I'Aube,  Atlas,  pl.  v. 

fig.  19. 

—  —       PEs-LEONis,  E.  Forbes.     Trans.  Geol.  Soc,  ser.  2,  vol.  vii,  p.  156, 

pl.  xviii,  fig.  5. 

1847.  —      NA.CS.OTTERJL,  A.  d'Orbigny.     Pal.  rran9.  Terr.  Crc't.,  vol.  iii,  p.  695, 

pl.  cccclxv. 

—  —       CARINATA,    d'Orbigny.     Ibid.,  vol.    iii.    j>.    "14,    pl.  cccclxxiv,  figs. 

1—5. 


344  CRETACEOUS   LAMELLIBRANCHIA. 

1847.     OsTBEA  FEONS,  d'Orbiguy.     Ibid.,  vol.  iii,  p.  733,  pi.  cccclxxxiii. 

—  —       MiLLETiANA,  d'Orhigmj.     Ibid.,  p.  712,  pi.  cccclsxii,  figs.  5—7. 

—  —       DiLTJviANA,  d'Orhifjny.     Ibid.,  p.  728,  pi.  cccclxxx. 

184-9.  —       MACROPTERA,  T.  Brown.     Illustr.  Foss.  Conch.  Gt.  Brit,  and  Ireland, 

p.  146,  pi.  Ivii),  figs.  1,  2. 

—  —       CAKINATA,  Brown.     Ibid.,  p.  146,  pi.  lix,  fig.  6. 

1850.  —  —  A.  (TOrhifjny.     Prodr.  de  Pal.,  vol.  ii,  p.  170. 

—  —  FEONS,  d'Orhigmj.     Ibid.,  p.  255. 

—  —  MACEOPTEEA,  d'OrUgiiy.     Ibid.,  pp.  84,  120. 

—  —  EicoRDEANA,  d'Orbigrty.     Ibid.,  p.  171. 

—  —  MiLLETiANA,  d'Orhig/iy.     Ibid.,  p.  139. 

—  —  DiLuviANA,  d'Orbigny.     Ibid.,  pp.  171,  198. 

—  —  FRONS    ET   CAEiNATA,    H.    B.    Gehiitz.     Das   Quadersandst.   oder 

Kreidegel).  in  Deutscli- 
land,  p.  196. 

—  —       DiLtrviANA,  Geinitz.     Ibid.,  p.  198. 

1852.  —       CARiNATA,  F.  Burner.     Kreidebild.  v.  Texas,  p.  75,  pi.  ix,  fig.  5. 
1851-2.      —  —         H.  G.  Bronn.     Letliaa  Geogn.,  ed.  3,  vol.  ii,  p.  262, 

pl.xxxii,  fig.  2. 

1853.  —       MiLLETiANA,  F.  J.  Pictet  and   W.  Roux.     Moll.  Foss.  Gres  verts 

de    Geneve,    p.    525, 
pi.  xlix,  fig.  3. 

1854.  —       MACROPTERA, /.  Mom's.     Cat.  Brit.  Foss.,  ed.  2,  p.  173. 

—  —       FRONs,  Morris.     Ibid.,  ed.  2,  p.  173. 

1855.  —       MACROPTERA,  G.  Cottcau.     Moll.  Foss.  de  I'Yonne,  p.  122. 

?  1859.         —       FRONS,  T.  Wiltshire.     Ked  Chalk  of  England  (Geol.  Assoc),  p.  16, 

pi.  ii,  fig.  4. 
1863.  —       DILUVIANA,  .4.  iTwM^/t.     Zeitschr.  d.  deutsch.  geol.  Gesellsch.,  vol.  XV, 

p.  724. 

1868.  —  —         E.  Eichwald.     Lethsea  Rossica,  vol.  ii,  p.  365. 

—  —       FRONS,  Eichwald.     Ibid.,  p.  366. 

—  —       CAEINATA,  Eichwald.     Ibid.,  p.  367. 

—  —       EECTANGULAEis,  J'.  J".  Piciei.     Melanges  paleont.,  p.  263,  pi.  xl,  fig.  9. 

1869.  —       MACEOPTEEA,   H.    Goquand.      Mon.    Ostiea,    Terr.  Crct.,  p.   164, 

pi.  Ixxii,  figs.  1 — 4. 

—  —       EECTANGULARis,  Coquand.     Ibid.,  p.  187,  pi.  Ixxii,  figs.  5 — 12. 

—  —       PECTiNATA,  Coquand.     Ibid.,  p.   76,  pi.   xxix,  figs.  1 — 7  (0.  colu- 

brina). 

—  —  SERRATA,  Coquand.     Ibid.,  p.  79,  pi.  xvii,  fig.  3  ;  pi.  xxs,  figs.  1 — 5. 

—  —  CAEINATA,  Coquand.     Ibid.,  p.  129,  pi.  xlix,  figs.  3 — 9. 

—  —  RicoEDEANA,  Coquand.     Ibid.,  p.  148,  pi.  liii,  figs.  8 — 12. 

—  —  MiLLETiANA,  Coquaiid.     Ibid.,  p.  155,  pi.  lix,  figs.  11 — 16. 

—  —  DILUVIANA,  Coquand.     Ibid.,  p.  120,  pi.  xl,  figs.  1—4. 

—  —  RECTAnavLA-Ris,  P.  de  Loriol  and   V.  Gillicron.     XJrgon.    iuft'r.  de 

Landeron,  p.  25, 
pi.   i,  figs.  20 — 
22. 
?  1870.         —       CAEINATA,  F.  EiJmer.     Geol.  v.  Oberschlesien,  p.  333. 


OSTREA.  345 

1871.  OsTEEA  [Alectryonia]  carinata,  F.  StoliczJca.     Pala;out.    ludica,    Cret. 

Fauna  S.  India,  vol.  iii, 
p.  468,  pi.  xlviii,  fig.  5  ; 
pi.  xlix,  figs.  1 — 2. 

—  —  —  PECTINATA,   Stoliczka.      Ibid.,    p.   4G9,    pi.    xlviii, 

figs.  1,  2. 

—  —  —  DiLUviANA,  Stoliczka.     Ibid.,  p.  466,  pi.  xlvi,  figs. 

1,    2  ;     pi.     xlvii,    figs. 
1,2. 

—  —       MACROPTERA,  F.  J.  Pidet  and  G.  Campiche.     Foss.  Terr.  Cret.  Ste. 

Croix  (Mater.  Pal. 
Suisse.ser.  6),p.  300, 
pi.  clxxxiv,  fig.  5. 

—  —       RECTANGULARis,  Pictd  and  Campiche.     Ibid.,  p.  275,   pi.  clxxxiv, 

figs.  1 — 4. 

—  —       MiLLETiANA,  Pictet  and  Campiche.     Ibid.,  p.  309,  pi.  cxciv,  figs. 

7-9. 

—  —       PECTisxTA.,  Pictet  and  Cam2}iche.     Ibid.,  p.  321. 

1872.  —       CARINATA,  H.  B.  Geinitz.     Das  Elbtbalgeb.  in  Sachsen  (Paleeonto- 

graphica,    vol.    xx,    pt.    1),    p.   174, 
pi.  xxxix,  figs.  6 — 11. 

—  —       DILUVIANA,  Geinitz.     Ibid.,  pt.  I,  p.  176,  pi.  xxxix,  figs.  1 — 5. 
?     —  —       FRONs,  Geinitz.     Ibid.,  pt.  2,  p.  30,  pi.  viii,  fig.  12. 

1875.  —       DILUVIANA,  E.  Hcbert  and  E.  Munier-Chahnas.     Annal.  Sci.  geol., 

vol.  vi,  p.  119. 

—  —       FBONS,  A.  J.  Jukes-Browne.     Quart.  Jouvu.  Geol.  See,  vol.   xxxi, 

p.  295. 

1876.  —       (Alectryonia)  diluviana,  D.  Brauns.     Zuitsclir.  f.  d.  gesammt. 

Naturwiss.,    vol.    xlvi, 
p.  392. 
1878.     Alectryonia  Zeilleri,  E.  Bayle.     Explicat.  Carte  geol.  France,  vol.  iv. 

Atlas,  pt.  1,  pi.  clxvi,  figs.  1 — 4. 

—  —       CARINATA,  Bayle.     Ibid.,  pi.  cxlvii,  figs.  1 — 7. 

1881.     OsTREA    CARINATA,   /.    Gosselct.      Escjuissc  gcol.    du    Noi'd,   iii,    pi.    xvii, 

fig.  4. 
?  1882.     Alectryonia  frons,  H.  Schriider.     Zeitsclir.  d.  deutscb.  gei>l.  Gesellsch., 

vol.  xxxiv,  p.  261. 

1883.  Ostrea  DILUVIANA,  A.  Fritsch.     Stud,  im  Gebiete  dcr  bijbm.  Kreideformat., 

iii,  Iserschicbt.,  p.  120,  fig.  95. 

—  —       FRONS  var.  MACROPTERA,   W.  Keeping.     Foss.,  etc.,  Neoc.  Upware 

and  Brickbill,  p.  102. 

—  —  —      var.  CARINATA,  Keeping.     Ibid.,  p.  103. 

1884.  —       MACROPTERA,    0.    Wecrth.      Neocomsaudst.  im  Teutoburg.-Walde 

(Palaeont.  Abhaudl.,  vol.  ii),  p.  55. 

—  —       RECTANGULARIS,  Weerth.     Ibid.,  p.  54. 

—  —       CARINATA,   C.  A.  White.     Foss.   Ostreidae  N.  America   (4th  Ann. 

Rep.  TJ.  S.  Geol.  Surv.),  p.  293,  pi. 
sliii,  figs.  1 — 4. 


346  CRETACEOUS   LAMELLIBRANCHIA. 

1886.     Alecteyonia    macroptera,    H.    Trautschold.      Neocom.    Sably     (Nouv. 

Mem.   Soc.  Imp.  Nat. 

Moscou,  vol.  xv),  p.  133. 

1888.     OsTREA  (Alectryonia)  diluviana,  G.  Miiller.      Jabrb.  d.  k.  preuss.  geol. 

Landesanst.  fiir  1887, 
p.  400. 
?  1889.         —       FRONS,  A.  Fritsch.     Stud,  im  Gebiete  der  buhm.  Kreideformat.,  iv, 

Teplitz.  Sebicht.,  p.  87,  fig.  86. 

—  —       (Alectryonia)    frons,    0.    Griepenkerl.      Senoii.  v.  Konigslutter 

(Paloeont.  Abhandl., 
vol.  iv),  p.  33. 
?  1890.     Allectrtonia  cf.  carinata,  M.  Yokoyama.     Palseontograpbica,  vol.  xxxvi, 

p.  198. 

1893.  Ostrea  frons,  S.Meunier.     Le  Naturaliste,  p.  175,  fig.  1. 

—  —       carinata,  B.  Michael.     Zeitscbr.  d.  deutscb.  geol.  Gesellscb.,  vol. 

xlv,  p.  238. 

—  —       sp.  cf.  DILUVIANA,  Michael.     Ibid.,  p.  239. 

1894.  —       DILUVIANA,  B.  Lundcjren.     Mollusk.  i  Mamniillahis  ocb  mucrortata 

zonerna,  p.  36. 

1895.  —       (Alectryonia)  carinata,  E.  Tiessen.      Zeitscbr.  d.  deutscb.  geob 

Gesellscb.,      vol.     xlvii, 
p.  462. 

—  —  —  rf.  diluviana,  Tiessen.     Ibid.,  p.  463. 

—  —       macroptera,  G.  Maas.     Ibid.,  vol.  xlvii,  p.  271. 

—  ■ —  —  A.  IVollemann.    Ibid.,  vol.  xlviii,  p.  834. 

1897.  —       CARINATA,  TJ.  Sl'/hle.     Geognost.  Jabresb.  (1896),  p.  40. 

—  —  —         B.  Leonhard.     Palasontograpbica,  vol.  xliv,  p.  27. 

—  —       diluviana,   a.    Hennicj.     Eevis.    Lamellibr.    i   Nilssons's    '  Petrit. 

Suecana,'  p.  16,  pi.  ii,  figs.  1,  2,  5. 

—  —       (Alectryonia)  pectinata,  F.  Ndtling.    U.  Cret.  (MaestricbtiiUi) 

Mari  Hills  (Palajont. 
Iiidica,  ser.  xvi,  vol.  i), 
p.  38,  pi.  ix,  figs.  2,  8. 

—  —  —  FRONS,  A.  Eiitot.     Bull.  Soc.  Beige  Geol.  Paleoiit. 

et  Hydrol.,  vol.  x,  p.  24. 
?     —  —       FRONS,  A.  Fritsch.      Stud,  im  Gebiete  der  bobm.  Kreideformat.,  vi, 

Cblomok.  Scbicbt.,  p.  68. 

1898.  —       pectinata,    G.    Miiller.     Mollusk.  Untersen.    v.   Braunscbweig  u. 

Ilscde    (Abbandl.    d.    k.    preuss.    geol. 

Landesanst.,  n.f.,  25),  p.  13,  pi.  i,  fig.  6. 
1900.         —       macroptera,  A.  Wollemann.      Die  Biv.  u.  Gastrop.  d.  deutscb.  u. 

bolliiud.  Neocoms  (ibid.,  n.f., 
pt.  31),  p.  16. 

1904.  Alectryonia  Zeilleri,  Jf.  Bouvilh'.     Mission  Sclent.  Perse  (J.  de  Morgan), 

vol.  iii,  pt.   vi,  Palt'ont.,  p.   277, 
pi.  xxxvi,  fig.  16. 

1905.  Ostrea  diluviana,  T.  Wegner.      Zeitscbr.  d.  deutscb.  geol.  Gesellscb.,  vol. 

Ivii,  p.  182. 


OSTREA.  347 

1908.     OsTREA  (Alectryonia)  maceoptera,  p.  a.  Peron.      Compte  rendu  Assoc. 

Franf.  Avanc.  Sci., 
vol.  xxxvi  (1907), 
p.  308. 

1910.  —  —  CARINATA,   E.   Buse.     Mon.    geol.    paleont.    Cerro 

de  Muleros  (Bol.  Instit. 
geol.  Mexico,  No.  25),  p. 
104,  pi.  xvi,  figs.  13,  14. 

1911.  —       (Alectronia)   cxRiNATA,  a.  Fritsch.     Stud,  im  Geldete  der  bohm. 

Kreideformat.,  Korycaner 
Schiclit.,  p.  48,  fig.  218. 

—  —       DiLUViANA,  Fritsch.     Ibid.,  p.  48,  fig.  216. 

—  Alectryonia  diluviana,  K.  Vogel  v.  Falclcenstein.     Zeitsclir.  d.  deutsch. 

geol.  Gesellsch.,  vol.  Ixii,  p.  659. 
?    —  —  cfr.  FRONS,  Vogel  v.  Falckenstein.     Ibid.,  p.  559. 

Nou  1847.     OsTREA  CARINATA,  J.  MHUer.     Petref.  der  Aachen.  Kreidef.,  pt.  ],  p.  38, 

(=0.  Goldfussi,  Holzapfel). 

—  1850.         —  —  /.  de  C.  Sowerhi/,  in  F.  Dixon.     Geol.  Sussex,  p.  357  {0. 

frons,  p.   386,  ed.  2), 
pi.  xxvii,  fig.  2. 

—  1852.         —       FROas  ?  B.  Ener.     Denksclir.  k.  Akad.  Wissenscli.  Wien,  Math. -Nat. 

CL,  vol.  iii,  p.  319,  pi.  xvii,  fig.  10. 

—  1883.        —  —        A.  Fritsch.     Stud,  im  Gebiete  der  bohui.  Kreideformat., 

iii,  Iserschicht.,  p.  121,  fig.  96. 


Description. — Sliell  nearly  equivalve ;  the  valves  similar  except  for  the  attached 
surface  of  the  left  valve.  The  proportion  of  height  to  length  varies,  but  usually 
the  height  is  much  greater  than  the  length,  the  difference  becoming  greater  with 
age.  Valves  usually  more  or  less  tapering  towards  the  postero-ventral  extremity, 
but  occasionally  expanding  at  the  end ;  slightly,  moderately,  or  considerably 
curved,  occasionally  forming  a  nearly  complete  volution ;  sides  flattened,  so  that 
in  the  elongate  forms  each  valve  is  roof-like  in  section.  The  thickness  (or  depth) 
of  the  valves  increases  with  age,  and  in  old  individuals  the  shell  becomes  very 
thick  and  possesses  a  vesicular  structure.  Umbones  siniill,  with  a  slight  or 
moderate  posterior  curvature.  A  posterior  wing  or  ear  is  usually  present,  and  is 
of  small  or  moderate  size  when  the  attached  surface  is  small,  but  of  large  size 
when  the  attached  surface  is  large  and  mainly  posterior  to  the  umbo.  A  small 
anterior  wing  is  often  present,  and  is  best  developed  in  specimens  which  have  a 
small  attached  surface.  When  the  attached  surface  is  small  or  narrow  the  shell 
becomes  elongate,  but  when  the  attached  surface  is  large  and  broad  the  shell 
becomes  rounded  or  oval  instead  of  elongate,  and  then  the  posterior  ear  is  usually 
not  distinctly  defined. 


348 


CRETACEOUS    LAIVIETJJBRANCHIA. 


109 


n.fo'-  ",?.«''','"? r""'  •^'■''^-  '^''-  ^'''^''y  I'-o^'ton^-.  Goulsby.  Bristol  Museum.  Left  valve  and 
anterior  view  100-102.  Lower  Greensand,  Atherfiekl.  Museum  of  Practical  Geology,  Nos.  25802  357«) 
valve'  lof  O^-  7'  ^"'l  i!"''^'-''"-  V-"-  lO:!,  Cmckers,  Atherfield.  Sa.ne  museum,  Xo.  25793. '  tl^^i 
vave"  °^'  "l^' J'""'^'-  «'-«^<^°«'i";l.  Upware.  Sedgvvick  Museum.  Interior  and  exterior  of  a  feft 
TrearhP,',  rT'  }^'"'-<'\^^^'-ff'^^^<i>  Far.ngdon.  106,  107,  Bristol  Museum.  Left  valve.  108.  Mr. 
va've      kll  X  °      ''       "•     ^"■^'  ^«"-"^"'0"^  S^"d^'  ShankUn.     Sedgwick  Museum.     Kight 


OSTREA.  349 

Valves  with  strong,  usually  angular  folds  which,  in  the  elongate  forms,  extend 
from  the  median  line  to  the  margin  ;  the  folds  are  usually  somewhat  curved,  but 
may  be  almost  straight;  the  amount  of  their  curvature  decreases  in  passing  from 
the  earlier  to  the  later  part  of  the  shell.  The  margins  of  the  two  valves  interlock 
by  means  of  sharply  pointed  tooth-like  projections  formed  by  the  interspaces 
between  the  folds.  On  the  median  ridge  of  the  valves  the  folds  are  usually 
irregular,  and  may  bear  on  each  side  of  the  ridge  short  spines ;  near  the  margins 
of  the  valves  long  tubular  outgrowths  occur  in  some  specimens.  The  number  and 
size  of  the  folds  vary  considerably  in  different  individuals ;  often  the  later  folds 
are  stronger  than  the  earlier  ones,  and  those  on  the  convex  side  stronger  than 
those  on  the  concave  side.  The  part  of  the  right  valve  near  the  umbo  is  smooth 
and  without  folds  so  long  as  the  corresponding  part  of  the  left  valve  is  attached  ; 
this  portion  is  commonly  small,  but  becomes  extensive  when  the  attached  surface 
of  the  left  valve  is  large,  and  then  the  folds  are  limited  to  the  relatively  small 
marginal  part  of  the  valves.  The  triangular  ligament-pit  may  be  slightly  or  con- 
siderably curved.  The  adductor  impression  is  oval,  and  usually  not  far  from  the 
hinge-line. 

Affinities. — The  examples  of  this  species  found  in  the  Lower  Cretaceous  have 
been  named  0.  rectanr/ularis,  Romer,  and  0.  macroptera,  Romer.  Pictet  and 
Campiche,  de  Loriol,  and  Weerth  regard  0.  macroptera  as  distinct  from  0.  rect- 
angularis,  and  state  that  the  former  differs  from  the  latter  principally  in  the 
relatiA'^ely  smaller  height  of  the  shell,  the  larger  posterior  wing,  and  the  larger 
ribs.  D'Orbigny,  Maas  and  WoUemann,  on  the  other  hand,  consider  that  the  two 
forms  cannot  be  separated.  The  last  author,  after  studying  a  large  collection  of 
specimens,  states  that  the  height  of  the  shell  depends  mainly  on  the  age  of  the 
individual ;  that  the  size  of  the  posterior  wing  varies  greatly,  being  in  some  cases 
quite  small,  in  others  very  large,  and  between  the  two  extremes  every  gradation 
may  be  found.  The  size  of  the  ribs  likewise  varies.  The  study  of  numerous 
English  specimens  leads  me  to  endorse  AVollemann's  view.  Pictet  and  Campiche 
figured  as  0.  macroptera  a  small  example  from  the  Lower  Greensand  of  Atherfield, 
but  larger  specimens  from  the  same  horizon  possess  a  higher  shell  like  0.  rcrt- 
anrjuJarls,  and  cannot  be  separated  from  0.  macroptera. 

The  examples  found  in  the  Lower  Cretaceous  deposits  have  been  generally 
regarded  as  distinct  from  those  in  the  Upper  Cretaceous,  which  in  this  country 
have  been  usually  named  O.frons  or  0.  carinata.  The  principal  distinction  is  said 
to  be  the  larger  posterior  wing  in  the  Lower  Cretaceous  form.  But  the  study  of 
a  large  series  of  specimens  shows  that  in  both  the  Upper  and  the  Lower  Cretaceous 
the  size  of  the  wing  varies  greatly,  as  well  as  the  height  and  curvature  of  the 
shell,  and  the  number  and  coarseness  of  the  ribs.  As  a  rule,  however,  the  posterior 
wing  is  better  developed  in  the  Lower  than  in  the  L^pper  Cretaceous  examples, 

46 


350 


CRETACEOUS   LA^IELLIBRANCHIA. 


Figs  110-122.— Osf,-ca  dihn-iana,  L.  Sedgwick  Museum,  except  120,  121.  110,  111,  Lower  Greensand, 
Upware  Left  and  right  valves.  112-119,  Lower  Groensaud,  Faringdon.  Lett  valves.  H-J-JJ*. 
anterior,  interior  and  e.tterior  of  a  left  valve.  116,  117,  interior  and  exterior  of  a  left  valve,  lis, 
119,  interior  and  exterior  of  a  left  valve.  120, 121,  zone  of  Peden  asper,  Devizes.  Museum  of  Practical 
Geology,  Nos.  25814,  2oS12.  120,  right  valve.  121,  left  valve.  122,  Chalk  Marl,  Folkestone.  Loft 
valve.     All  x  J. 


OSTREA.  351 

but  in  some  of  the  formei'  it  is  small/  while  in  some  of  the  latter  it  attains  a  large 
size  (fig.  123),  and  such  specimens  are  indistinguishable  from  0.  mncroptera.  It 
seems,  therefore,  that  no  line  can  be  drawn  between  0.  macro2)ter(t  and  the  Upper 
Cretaceous  forms,  especially  since  it  is  found  that  the  size  of  the  wing  is  directly 
related  to  that  of  the  attached  surface  of  the  left  valve  which  was  almost  certainly 
determined  by  external  conditions.  When  the  attached  surface  is  large  and 
mainly  posterior  to  the  umbo,  then  the  macropfera  type  with  a  large  wing  arises. 

The  examples  of  this  species  (here  known  as  0.  diluviana,  L.),  found  in  the 
Upper  Cretaceous  deposits,  have  received  numerous  names,  of  which  the  principal 
are  0.  pcctlnata,  Lamarck,  0.  carinata,  Lamarck,  0.  coluhrina,  Lamarck,  0.  froiis, 
Parkinson,  0.  t^errafa,  Brongniart,  0.  pn'onota,  Goldfuss,  0.  Millrtidvu,  d'Orbigny, 
0.  BlrorJcana,  d'Orbigny,  0.  Zeilleri  (Bayle).  In  the  LTpper  Cretaceous  of  England 
this  species  is  not  known  to  occur  above  the  zone  of  Holaster  suhjlohnsus  and  has 
been  usually  named  O.frons  or  0.  mrlnnta,  but  on  the  continent  of  Europe  and  in 
other  parts  of  the  world  it  is  represented  in  the  higher  parts  of  the  Chalk. 
D'Orbigny  and  Coquand,  believing  in  the  principle  that  specimens  found  at  different 
horizons  belong  to  different  species,  have  regarded  as  distinct  forms  the  following 
amongst  others  :  0.  Milletiana  from  the  Gault,  0.  carinata  from  the  Cenomanian,  0. 
pedviafa  (O.fronx)  from  the  Lower  Senonian,  0.  scrrata  from  the  Upper  Senonian. 
But  later  authors  have  found  the  o'reatest  difficult v  in  distiuQ-uishino-  these 
"  species."  An  examination  of  a  large  number  of  specimens,  even  when  collected 
from  one  locality  and  one  horizon  only,  shows  that  the  shell  is -extraordinarily 
variable,  and  that  every  gradation  is  found  between  the  different  types  ;  apart  from 
variation  in  the  number  and  size  of  the  ribs,  the  curvature  of  the  shell,  etc.,  there 
are  differences  which  are  obviousl}^  duo  to  the  size,  shape  and  position  of  the 
attached  surface.  Similar  modifications  occur  at  all  horizons,  and  it  seems 
impossible  to  separate  as  distinct  species  the  forms  found  at  different  levels. 
Sometimes  at  one  locality  or  in  one  kind  of  deposit  a  particular  form  of  the  shell 
may  be  more  common  than  others,  and  may,  if  only  a  small  number  of  specimens 
are  available,  give  the  impression  of  l)eing  a  distinct  species,  but  whenever  a  large 
collection  is  made  other  varieties  are  found  which  make  it  impossible  to  regard  as 
a  species  the  form  which  at  first  sight  appeared  to  be  distinct.  The  difficulty  of 
separating  these  supposed  species  is  shown  by  the  fact  that  although  d'Orljigny 
states  that  0.  froiis  is  characteristic  of  the  Senonian,  yet  he  includes  in  his  synonymy 
the  specimens  figured  by  Sowerby  from  the  Upper  Greensand  and  Chalk  Marl. 
Similarly,  in  quoting  foreign  examples  of  a  "  species,"  authors  have  sometimes 
unconsciously  cited  them  from  horizons  in  which  they  believed  the  species  did 
not  occur. 

'  See,  for  example,  a  specimen  from  the  Lower  Greeusaud  of  Faringdon  (figs.  106,  107),  in 
whieh  the  left  valve  was  attached  to  a  long  narrow  object,  and  tlie  posterior  wing  is  not  developed. 


352  CRETACEOUS   LAMELLIBRANCHIA. 

Peron  (1908)  has  already  recognised  that  these  "species  "  cannot  be  accepted. 
He  states  that  the  detailed  analysis  of  the  characters  attributed  to  each  of  the 
species  and  the  study  of  their  synonymy  shows  that  the  enchainemeut  of  these 
diverse  forms  is  complete,  and  that  usually  the  difference  of  names  corresponds 
only  to  difference  of  stratigraphical  horizon. 

The  form  found  in  the  Gault,  which  was  named  0.  Milletiaim  by  d'Orbigny,  is 
considered  by  Pictet  and  Campiche  to  be  identical  with  0.  carinata  of  Sowerby 
from  the  Upper  Greensand  and  Chalk  Marl,  which,  as  already  mentioned,  is 
included  by  d'Orbigny  in  0.  frons  of  the  Senonian.  Pictet  and  Campiche  quote 
0.  Milletiana  from  the  Cambridge  Greensand,  but  this  is  included  by  Jukes- 
Browne  in  0.  frons. 

0.  diliiviaua,  Linngeus,  from  the  Upper  Chalk  of  Sweden,  was  figured  first  by 
Nilsson,  and  more  recently  other  figures  of  Swedish  specimens  have  been  given  by 
Hennig  (1897).  D'Orbigny  and  Coquand  recognised  that  the  specimens  figured 
by  Nilsson  as  0.  dilnviana  could  not  be  separated  from  0.  frons,  and  the  same 
view  is  held  by  Brauns,  Lundgren,  and  Hennig.  The  two  last-named  authors 
state  that  Nilsson's  figures  certainly  represent  Linnaeus'  species,  and  Brauns  also 
takes  them  as  types  of  0.  diluviana,  but  excludes  the  figures  given  by  d'Orbigny^ 
Coquand,  Goldfuss  and  Geinitz.  D'Orbigny,  on  the  other  hand,  takes  Hisinger's 
figure  of  a  specimen  from  the  Upper  Chalk  of  Sweden  as  the  type  of  Linnaeus' 
O.  diluvinna,  and  excludes  from  that  species  the  forms  figured  by  Nilsson,  which 
he  regards  as  belonging  to  0.  frons.  The  examples  of  0.  diluviana  figured  by 
d'Orbigny,  Coquand  and  Geinitz  come  from  the  Cenomanian.  In  0.  diluviana,  as 
understood  by  those  authors,  the  shell  is  oval  or  rounded  in  form  instead  of  being 
elongate  as  in  the  common  forms  of  0.  frons ;  at  first  sight  it  appears  to  be  quite 
distinct,  and  being  easily  recognisable  it  has  been  commonly  regarded  as  a  separate 
species,'  but  Lundgren  and  Hennig  have  found  in  the  Swedish  Chalk  a  large 
number  of  intermediate  forms  which  link  together  0.  diluviana  as  interpreted  by 
d'Orbigny  and  0.  diluviana  as  figured  by  Nilsson  and  Hennig,  consequently  these 
two  types  cannot  be  any  longer  regarded  as  distinct  species.  Geinitz,  although 
keeping  the  foi*ms  distinct,  nevertheless  recognises  in  the  Cenomanian  of  Saxony 
the  existence  of  intermediate  forms,  and  the  same  fact  is  shown  by  Goldfuss' 
figures.  An  oval  or  rounded  form,  closely  resembling  0.  diluviana  as  understood 
by  d'Orbigny,  is  found  in  the  Lower  Greensand  of  Faringdon  (figs.  115,  118, 
119),  and  is  certainly  inseparable  from  the  common  elongate  form  which  has 
been  usually  named  0.  macroptera  ;  similar  remarks  apply  to  a  rounded  form  found 
occasionally  in  the  Upper  Greensand  and  Chalk  Marl  of  England  (figs.  124,  125). 

^  H.  Douville  places  this  iu  the  "genus"  Loplia  {—  Aledryonia),  aud  refers  the  elongate  forms 
{frons,  carinata,  etc.)  to  the  "  genus  "  ^rc^osirea.  See 'Bull.  Soc.  gcol.de  France,' ser.  4,  vol.  x 
(1910),  pp.  63G,  637. 


OSTREA. 


353 


Fios.  123-134. — Osliea  diliiviana,  L123,  zone  of  Sehloenbachia  roslrala,  Devizes.  Musouiii  of  Practical 
Geology,  No.  25820.  Riffht  valve.  124,  12."),  Upper  Greensaiul,  Sidinoutli.  Briti.sli  Museum,  L3326. 
Left  valve.  12(i  130,  Clialk  Marl,  Folkestone.  Se(l<;wick  Museum.  12G,  anterior  view.  12S-130, 
right  valves.  127,  anterior  view  of  128.  131-133,  Base  of  Chalk  Marl,  HaslingfieU.  Sedgwick 
Museum.  Right  valves.  13t,  Cenomanian  Sandstone,  Wilmington.  Sedgwick  Museum.  Vertical 
section  of  left  valve.     All  x  J-. 


354 


CRETACEOUS   LAMELLIBRANCHIA. 


So  that  this  type  occurs  at  three  horizons  :  Aptian,  Cenomariian,  and  Senonian, 
and  its  features  are  obviously  due  to  the  harge  size  and  rounded  form  of  the 
attached  surface;  the  shell  was  attached  for  such  a  long  period  that  when  it 
eventually  grew  free  it  was  unable  to  develop  its  usual  elongate  form,  and  its 
ultimate  outline  was  only  a  little  different  from  that  of  its  attached  surface. 
The  coarseness  of  the  ribs  varies  in  the  same  way  as  in  the  elongate  forms.  In 
some  places,  as,  for  instance,  in  the  Cenomanian  of  Gamighiigel  in  Saxony,  the 
shell  attains  a  great  thickness,  but  the  elongate  forms  likewise  sometimes  become 
very  thick. 


Figs.  135-138. — Ostrea  dihti-iana,  L135,  zone  of  Molasier  sulgloboswt,  Cherry  Hintou.  Kijjht  valve.  13G-13S, 
Base  of  Chalk  Marl,  Haslingfield,  Cambs.  136,  137,  Right  valves.  138,  anterior  view  of  137. 
Sedgwick  Museum.     All  x  ^. 

0.  santonensis,  d'Orbigny,  and  0.  carantonensix,  d'Orbigny,  are  similar  to 
d'Orbigny's  0.  diluviana,  and  are  included  by  Geinitz  in  that  species. 

Bemarls. — The  shell  varies  greatly  in  its  curvature,  some  examples  being  only 
slightly  bent,  while  others  form  almost  a  complete  volution  (fig.  123),  and  between 
these  extremes  every  gradation  is  found.  The  variation  in  the  coarseness  of  the  ribs 
seems,  in  some  cases  at  any  rate,  to  be  connected  with  the  nature  and  depth  of 
the  sea-floor  on  which  the  individuals  lived  ;  for  example,  most  of  the  specimens 
found  in  the  Chalk  Marl  have  coarse  ribs,  but  those  found  in  the  Cenomanian 
sandstone  of  "Wilmino-ton  in  Devon  have  smaller  and  more  numerous  ribs.  Occa- 
sionally  folds  or  ribs  are  developed  on  the  posterior  ear  (fig.  135).  The  long 
regular  outgrowths  from  the  margin  of  the  valves  (fiig.  122)  occur  in  specimens 


OSTREA.  355 

from  the  Chalk  Marl,  and  were  no  doul)t  developed  for  the  purpose  of  fixation  in 
the  soft  sediment  of  the  sea  floor. 

In  all  cases  the  right  valve  starts  with  a  smooth  stage,  and  folds  are  developed 
later.  The  smooth  stage  corresponds  with  the  attached  surface  of  the  left  valve, 
since  folding  does  not  begin  until  the  margin  of  that  valve  groAvs  free  from  the 
rock  or  body  to  which  the  shell  is  fixed.  Occasionally,  after  folding  has  gone  on 
for  some  time,  a  second  smooth  stage  appears  on  the  right  valve ;  this  is  due  to 
the  left  valve  becoming  again  attached  to  a  foreign  body  (fig.  137). 

Types. — 0.  dilaviana,  L.,  from  the  Senonian  of  Sweden.  0.  j'i'ctiiiatu,  Lamarck, 
is  said  to  have  come  from  near  Dreux  (Eure-et-Loire).  0.  carinata,  Lamarck, 
from  Carry  (Seine-Inferieure).  0.  frons,  Parkinson,  from  France;  the  locality 
and  horizon  are  unknown,  and  the  specimen  cannot  now  be  found.  0.  carinata, 
Sowerby,  from  the  Upper  Greensand  of  Chute  Farm,  near  Longleat  Park,  and  from 
the  Chalk  Marl  of  Folkestone,  are  in  the  British  Museum.  0.  scrrata,  Cuvier  and 
Brongniart,  came  from  Dreux.  0.  viacrojitera,  Sowerby,  from  the  Lower  Greensand 
of  Folkestone,  is  in  the  British  Museum.  0.  retusa,  Sowerby,  from  the  Lower 
Oreensand  of  Atherfield,  cannot  be  traced. 

Distribution. — Claxby  Ironstone  (zone  of  Belemnites  lateralis)  of  South  Willing- 
ham.  Tealby  Limestone  (zone  of  Belemnites  hrunsvicensis)  of  North  AYillingham, 
Lincolnshire.  Ferna-hed  of  Atherfield.  Ferruginous  Sands  of  Atherfield  and 
Shanklin.  Recorded  by  Topley  from  the  Sandgate  Beds  and  Folkestone  Beds  of 
Folkestone.     LoAver  Greensand  of  Faringdon,  Brickhill,  Potton  and  Upware. 

Upper  Gault  of  Folkestone.  Cambridge  Greensand.  Upper  Greensand  (zone 
of  Schlcenhachia  rostrata)  of  Blackdown,  Devizes,  "Warminster  and  Ventnor. 
L'pper  Greensand  (zone  of  Fecten  asper)  of  Devizes.  Chalk  Marl  (zone  of  Schloni- 
hachia  varians)  of  Ventnor,  Folkestone,  Haslingfield,  Burwell,  etc.  Cenomanian 
Sandstone  of  Wilmington.  Cenomanian  (Meyer's  Bed  12)  of  Dunscombe.  Zone 
of  Holaster  snbglohosus  of  Cherry  Hinton  and  Burwell. 


OsTKKA  LKYirEKir,  Lmjmerie  [ex  Deshayes],  1842.     Text-figs.  139,  140. 

1842.  OsTREA  Leymbeii,  [Desbaves,  MS.],  A.  Leijmerie.       ili'm.  Soc.   geol.   de 

Fiance,  vol.  v,  pp.  11,  28,  pi.  xiii, 
fig.  4. 
1845.         —  —        E.  Forbes.     Quart.  Joiu-n.  Geol.  Soc,  vol.  i,  p.  250. 

1843.  —  —        A.  Leymerie.     Statist,  gi'ol.  inin.  de  I'Aube,  Atlas,  pi.  vii, 

fig.  2. 
1847.         —  —A.  d'Orbigni/.     Pal.  Frau?.  Terr.  Cret.,  vol.  iii,  p.  704, 

pi.  cccclxix,  tigs.  1 — 3. 
1850.  —  —         iVOrhignij.     Prodr.  de  Pal.,  vol.  ii,  p.  108. 

1854.         —      Leymeeiei,  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  173. 


356 


CRETACEOUS   LAMELLIBRAXCHIA. 


1855.     OsTREA.  Leymerii,  G.  Cutleau.     Moll.  Foss.  de  I'Youne,  p.  Hi. 
I860.  —  —         A.  Gaudrij.      Bull.  Soc.  gcol.  de  Prance,  ser.  2,  vol.  xvii, 

J,.  30. 
?1861.  —  —         P.deLnriol.     Auiui.  luveit.  Foss.  ilt.  Saltve,  p.  112. 


\ 


Fig.  139.  — Osdva  Leymerii,  Lcym.     MammiUatiis-hcd,  Okefoi'd  Fitzpaine.     British  Museum,  No.  L11597. 

Eight  valve,      x  J. 

1869.         —  —        H.  Coquand.     Men.  Ostrea.  Terr.  Crct.,  p.  179,  pi.  Ixx, 

figs.  14 — 17  ;  pi.  Ixxi,  figs.  6,  7. 
—      Leymeriei,  p.  de  Loriol  and  V.  GUlieron.     Urgon.  lufc'r.  du  Lau- 

deron,  p.  27. 
1871.  —      ljV.YiiY.iiu,  F.  J.  Pidd  and  G.Campiche.  Terr.  Crt't.Ste.  Croix  (Mater. 

Pal.  Suisse,  ser.  5),  p.  296,  pl.  cc,  figs.  1,  2. 


OSTREA.  357 

1878.     OsTEEUM  Leymeriei,  E.  Baijle.     £xplica(.  Carle  gt'ol.  Je  France,  vol.  iv, 

Atlas,  pt.  1.  i<].  cxxx,  figs.  1,  2. 
1897.     O.STREA  Leymeriei,  R.  B.  Nenion.      Proc.  Dorset  Nat.  Hist,  aiid  Antiq. 

Field  Club,  vol.  xviii,  p.  73,  pi.  i, 

fig.  3. 

Description. — Shell  large,  very  thick  in  old  specimens,  higher  than  long; 
nsnally  slightly  or  only  moderately  inequilateral ;  outline  ovate,  oval,  subtrigonal 
or  subquadrate.  Left  valve  slightly  or  moderately  convex ;  right  valve  often 
flattened.     Umbonal  part  sometimes  nan-ow,  sometimes  broad.     Umbo  straight  or 


•^•r/ 


Fig.  1-10. — Ostrea  Leijmcrii,  Leym.     Mammillat iis-heA,  Okofoitl  Kitzpaine.     Briti.sb  Museuiu,  No.  L.  11591. 

Interior  of  part  of  right  valve,      x  ^. 

slightly  curved  ;  area  large,  high.  Surface  of  valve.s  sometimes  smooth,  except 
for  growth-lamellge,  sometimes  with  radial  folds.  Attached  surface  of  vari- 
able size. 

Affinities. — This  species  seems  to  be  related  to  0.  Germaini,  Coquand.  It  also, 
as  de  Loriol  pointed  out,  shows  some  resemblance  to  some  forms  of  E.eogijra 
sinuata  in  which  the  umbo  is  only  slightly  curved;  but  whether  it  has  any -real 
relationship  to  that  species  cannot  at  present  be  determined.  See  also  0.  cuna- 
hiiht  (below). 

Ti/jje. — From  the  Barremian  of  Aube. 

47 


358 


CRETACEOUS   LAMELLIBRANCHIA. 


Distribution. — Hythe  Beds  of  Aylesford,  Kent.  ManiiitiUdtun-heiX  of  Okeford 
Fitzpaine,  Dorset.  Recorded  by  Fitton  from  the  Perna-heA  and  Ferruginous 
Sands  of  Atlier field.  Recorded  I)}'  Topley  from  the  Atlierfield  Beds  of  Peasmarsh 
and  Sevenoaks. 


OsTREA  cuxAiJL-i.A,  ,SVv'%,  18G1.     Text-figs.  141,  1-12. 

1861.     OsTREA  C0NABULA,  H.  G.  Seeleij.     Ann,  Mag.  Nat.  Hist.,  ser.  3,  vol.  vii,  p. 

117,  pi.  V,  fig.  1. 
—  —        LAGENA,  Seeleij.     Ibid.,  p.  117,  pi.  v,  fig.  2. 

Beacripfidii. — Shell  higher  than  long,  either  nearly  equilateral  or  slightly  or 


Fig.   141. — Ostrea   cunabiila.  Seel.     Cambridge   Greensand  (base  of  Chalk  Marl).      Sedgwick   Museum. 
Cambridge.    The  type  of  0.  lagena.  Seel.     Interior  and  exterior  of  left  valve,      x  =. 

moderately  inequilateral  ;  when  nearly  equilateral  the  outline  is  often  ovate 
or  oval. 

Left  valve  ■with  the  attached  surface  either  small  and  near  the  umbo  only,  or 
large — sometimes  extending  to  the  greater  part  of  the  valve  ;  in  the  former  case 
the  valve  is  very  convex,  in  the  latter  slightly  convex  or  flattened.  Umbonal  jjart 
usually  narrow  and  pointed.  Area  large,  usually  higher  than  long  ;  sometimes  in 
the  plane  of  the  valves  and  nearly  symmetrical ;  in  other  cases  curving  inwards, 
outwards  or  backwards.  Surface  usually  with  numerous,  rounded,  radiating  ribs 
crossed  by  growth-ridges.  Adductor  impression  deep,  near  the  posterior  margin, 
oval  or  more  or  less  quadrate.     Right  valve  nearly  flat,  with  growth-lines  only. 

Affinities. — 0.  cnnahxda   is  closely  allied    to    and    may    be   only   a   variety    of 


OSTREA. 


359 


Fio.  142. — Ostrea  ninahuJa,  Seel.  Cambridge  Greensand  (base  of  Chalk  Marl).  A,  b,  British  Museum, 
Xo.  ()77K1.  c-i.  Sed|j:wick  Museum.  A,  B,  left  valve,  c,  left ;  d.  right  valve  ;  B,  antt^rior  view  of  c,  D. 
F.  rii;ht  valve  with  other  oysters  on  the  surface,  a,  left  valve.  H,  i,  exterior  and  interior  of  a  left  valve. 
All  x  §. 


360  CRETACEOUS   LAMELLIBRANCHIA. 

0.  Lpijmen!,  from  which  it  appears  to  differ  in  its  somewhat  smaller  ril)s.  The 
forms  with  a  small  surface  of  attachment  resemble  O.bdis.^unensis,  Bohm/  but  have 
coarser  and  less  regular  ribs.  0.  lagena,  Seeley  (fig.  141),  is  a  form  of  0.  cuwilmhi 
with  a  very  large  attached  surface,  and  consequenth-  a  less  convex  left  Aalve. 

Tiipes. — From  the  Cambridge  Greensand  (indigenous).  The  type  of  0.  hiijriiii 
is  in  the  Sedgwick  Museum,  Cambridge ;  the  type  of  0.  cinialiula  cannot  be  found, 
but  other  specimens  named  by  Seeley  are  in  the  Sedgwick  IMuseum. 

Dititrihiition. —  Cambridge  Greensand  (base  of  Chalk  ]\Iarl),  Camljridge.  Chalk 
Marl  of  Burwell. 


OsTREA  W.\i.Ki:i;i,  Krrpiinj,  1883.     Plate  LY,  figs.  1—3. 

1883.     OsTREA  Walkeki,  W.  Keepiiaj.     Foss.,  etc.,  Neoc.  Upware  aud  Bric-khill, 

p.  103,  pi.  iv,  fig.  4. 

Reiiuirlcs. — This  fonn  is  similar  to  0.  Germaini  and  0.  Li'i/iiicrii;  the  chief 
difference  mentioned  by  Keeping — the  inequality  of  the  valves — is  not  constant, 
and  is  determined  b}'  the  size  of  the  attached  surface.  Harbort  regards  0.  ]\'(illien 
as  a  synonym  of  0.  Germaini,  Coquand,-  but  the  material  available  is  hai-dly 
sufficient  for  definite  determination.  Some  of  the  specimens  with  a  large  attached 
surface  resemble  0.  Oxmana,  AVoliemann.'' 

TijiH\ — In  the  Sedgwick  Museum,  Cambridge, 

Distribiilion. — Lower  Greensand  of  Upware. 


OsTiiEA  VKsirri,Ai(is,  Lauunrh,  180(1.    Plate  LV,  figs.  4—0.    Text-figures.  14:5—182. 

1779.         —  B.  Faujas-St.-Foitd.    Hist.  imt.  Mto.  St.  Pierre  de  Maestricht, 

jil.  xxii,  fig.  4;  jil.  XXV,  figs.  2,  5. 
18Ut).     OsTREA  VESicuLARis,  Lamars}:.     Ann.  Mus.  Hist,  uat.,  vol.  viii,  p.  IGO,  aud 

vol.  xiv  (1809),  p.  375,  pi.  xxii,  fig.  3. 
—  —       DELTOlDEA,   Laiiiarch.      Ibid.,   p.   160;   vol.  xiv  (1809),  p.  374,  pi. 

xxi,  fig.  3  (uou  deJtoidea,  Sowerbv). 
1816.  — ■    ,  ir.  SinitJi.    Strata  ideiitif.  Organised  Fossils,  p.  7,  pi.  iii,  figs.  5 — 7. 

1819.  —      VESICULARIS,  Lamarck.     Aiiimaux  sans  Vert.,  vol.  vi,  p.  2Ut. 

1820.  —     CONVEXA,  T.  Say.     Amer.  Journ.  Sci.,  vol.  ii,  p.  42. 

1  '  Zeitschr.  d.  deutsch.  geol.  Gesellsch.,'  vol.  li  (1899),  p.  46(5,  pi.  xxix,  figs.  1—3. 

-  Coquand,  '  Mon.  Ostrea,  Terr.  Cn't.'  (1869),  p.  191,  pi.  Ixvi,  figs.  14—16.  Pictet  and  Canipiclie, 
'Terr.  Crct.  Ste.  Croix'  ('Mater.  Pal.  Suisse,'  ser.  5,  1871),  p.  '295,  pi.  clxxxix,  figs.  1—6.  Wolle- 
mauu,  '  Bivalv  ii.  Gastrop.  deutsoli.  u.  hoUiindisch.  Neocoms '  (1900),  ji.  18,  pi.  i,  fig.  4.  Harbort, 
'Fauna  Sehaumburg-Lippe'scheu  Kreidemulde  '  (1905),  p.  28. 

3  Op.  cit.  (1900),  p.  19,  pi.  i,  fig.  5,  pi.  ii,  fig.  1. 


OSTREA.  3G1 

1822.  OsTEEA  vEsicuLAEis,  A.  Bvoiiijniart .      In  Cuvier,  Osseiueus  Foss.,  vol.  ii, 

p.  598,  pi.  iii,  fig.  5. 

1823.  GRTPHiEA   OLOBOSA,   /.    de    C.   Sowerhij.      Min.    Conch.,   vol    iv,    [i.    127, 

pi.  cecxeii. 

1827.  OsTREA  VESICULAEIS,  6'.  Nilssoii.    Petrific.  Suecana,  p.  29,  pi.  vii,  figs.  8 — 5; 

pi.  viii,  figs.  5,  6. 

—  —        HippopoDiuM,  Nilss'ni.     Ibid.,  p.  'SO,  pi.  vii,  fig.  1. 

—  —        CLAVATA,  Nilssun.     Ibid.,  p.  30,  pi.  vii,  fig.  2. 

1828.  Gryphjea  convexa,  S.  G.  Morton.     Journ.  Acad.  Nat.  Sci.  Philad.,  vol.  vi, 

p.  79,  pi.  iv,  figs.  1,  2. 

—  —  MUTABiLis,  Morton.     Ibid.,  \).  81,  pi.  iv,  tig.  3. 

1832.  —  EXPANSA,  J.  de  C.  Soicerby.     lu  Sedgwick  and  Murcliison,  Trans. 

Geol.  See,  ser.  2,  vol.  iii,  pp.  349, 
418,  pi.  xxxviii,  fig.  5. 

—  OsTREA   vEsicuLARis,    6r.    P.   Deskaijes.     Hist.  uat.  Vers    et   Mollusques 

(Encycl.  method.),  vol.  ii,  p.  291. 

1833.  —  —  A.  Gohlfiis.'i.     Petref.  Gei-m.,  vol.  ii,  p.  23,  pi.  Ixxxi, 

fig.  2. 

—  —        HIPPOPODIUM,  Goldfuss.     Ibid.,  p.  23,  pi.  Ixxxi,  fig.  1. 

1834.  GBYPH.a:A  convexa,  S.  G.  Morton.     Synopsis  Org.  Remains  Cret.  U.  States, 

p.  53,  pi.  iv,  figs.  1,  2. 

—  —  MUTABILIS,  Morton.     Ibid.,  p.  53,  pi.  iv,  fig.  3. 

?  1835.     Ptcnodonte  eadiata,    G.  Fischer  de    Wuldheim.     Bull.    Soe.   Imp.    Nat. 

Moscou,  vol.  viii,  p.  119,  pi.  i. 

1837.  OsTREA  VESICULAEIS,  W.  Hisitiger.     LethEea  Suecica,  p.  46,  pi.  sii,  fig.  2. 

—  —       HIPPOPODIUM,  Eisinger.     Ibid.,  p.  47,  pi.  xiii,  fig.  4. 

—  —       CLAVATA,  Hisinijer.     Ibid.,  j).  47,  pi.  xiii,  fig.  3. 

—  GRYPHiEA  siMiLis,  G.  G.  Pusch.     Poleus  Paliiont.,  p.  34,  pi.  iv,  fig.  12. 

—  Osteea  VESICULAEIS,  A.  d'ArcMac.    Mem.Soc.  gt'ol.de  France, vol.  ii,p.  183. 
?    —  —        PROBOSCIDEA,  d'Archiac.     Ibid.,  p.  184,  pi.  xi,  fig.  9. 

?    —  —        VESICULARIS,  F.  Dnjarditi.     Ibid.,  vol.  ii,  p.  229. 

1838.  GBYPHiEA  VESICULARIS,  H.  G.  Bronn.     Letbsea  Geogn.,  vol.  ii,  p.  204,  pi. 

xxxii,  fig.  1. 
1842.  —  (Ostrea)  yEsicvi.AB.is,  F.  v.  Hagenoic.    Neues  Jabrb.  fiir  Min., 

etc.,  p.  548. 
1845.     Gryph^ea   VESICULARIS,    H.    B.    Geinitz.      Gnmdr.     d.  Verstein.,  p.  483, 

pi.  XX,  figs.  17,  18. 
1845.     Ostrea  vesicularis,  A.  d'Orhigny.      In  Murchison,   de  Verneuil  and  de 

Keyserliug,      Gi'ol.     Russie     de 
I'Enrope,  vol.  ii,  p.  491. 
184ti.         —  —  A.  Leymerie.     Statist,  gt'ol.  min.  de    I'Aube,   Atlas, 

pi.  iv,  fig.  1. 

—  —  —  A.  E.  Reuse.    Die  Verstein.  der  biihm.  Kreideforuiat., 

pt.  2,  p.  37,  pl.  xxix,  figs.  21.  22;  pl. 
XXX,  figs.  1 — 8. 

—  HIPPOPODIUM,  Betiss.     Ibid., p.  39,  pl.  xxviii,figs.  10 — l.j.  17, 18 

pi.    xxix,    figs.     1  — 18;    j)l.    XXX,    figs. 
13,  14  (r  2>c>'ti»t)- 


302  CRETACEOUS   LAMELLIBRAXCHIA. 

1847.      OsTREA  HippopODiuM,  A.  iVOrbiijiiy.     Pal.  Frau9.  Terr.  Crct.,  vol.  iii,  p. 

731,  pi.  cccdxxxi,  figs.  4 — 6 ;  pi. 
cccclxxxii. 

—  —         VESicuLARis,  d'OrhiijHij.     Ibid.,  p.  742,  pi.  cccclxxxvii. 

—  —  —  /.  Mailer.     Petref.  der  Aachen.  Kreidef.,  pt.  1,  p.  37. 

—  —        HIPPOPODIUM,  Midler.     Ibid.,  p.  39. 

1849.  Grtph.ea  globosa,  J.  Broirn.      Illustr.   Foss.  Conch.  Great  Britain  and 

Ireland,  p.  148,  pi.  Ixi,  fig.  2. 

1850.  —  —        var.  DEPREssA,  J.  de  C.  Sotverbij,  in  F.  Dixon.     Geol. 

Sussex,  p.  357,  pi.  xxvii,  fig.  3. 

—  OsTEEA  SP.,  Sowerby.     Ibid.,  p.  357,  pi.  xxviii,  figs.  22,  23. 

—  Gryph^a  VESICULARIS,  E.  Kiier.     Kreidemerg.  v.  Lemberg  (Haidiuger's 

NatuiTviss.  Abhaudl.,  vol.  iii,  pt.  2), 
p.  30. 

—  OsTREA  VESICULARIS,   A.   Altli.     Geogn.-palsBont.   Beschreib.  v.  Lembei'g 

(ibid.,  vol.  iii,  pt.  2),  p.  252. 
?    —  —  HIPPOPODIUM,  Alth.     Ibid.,  p.  253,  pi.  xiii,  fig.  3. 

—  —  VESICULARIS,  A.  d'Orbigny.     Prodr.  de  Pal.,  vol.  ii,  p.  256. 

—  —  Lesueuri,  d'Orbigny.     Ibid.,  p.  171. 

?  1851.  —  NiLSSONi,  /.  Midler.     Petrefact.  Aachen.  Kreidef omiat.,  pt.  2, 

p.  70. 

—  VESICULARIS,  A.  Leymerie.      Mem.  Soc.  gcol.  de  France,  ser.   2,  vol.  iv, 

p.  202,  pi.  X,  figs.  2,  3. 
1851-2.     GRYPH.t;A  VESICULARIS,  H.  G.  Bronn  and  F.  Riimer.     Lethsea   Geogn., 

ed.  3,  vol.  ii,  pt.  5,  p.  264,  pi.  xxxii,  fig.  1. 
1852.  —  —  B.  Kiter.      Denkschr.  Akad.  Wisseusch.  Wien, 

Math.-uat.  CI.,  vol.  iii,  p.  319. 
?    —         OsTJiEA  VESICULARIS  var.  AUCELLA,  F.  Biimer.    Kreidebild.  v.  Texas,  p.  74, 

pi.  ix,  fig.  4. 
1854.         —       HIPPOPODIUM,  J.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  173. 

—  —       VESICULARIS,  Morris.     Ibid.,  p.  174. 

1863.  GRTPH.SEA  VESICULARIS,  K.  E.  SchafMutl.     Siid-Bayerns  Lethsea  Geogn., 

p.  143,  pi.  xli,  figs.  5,  6. 

—  OsTREA  VESICULARIS,  A.  V.  Strombech.     Zeitschr.  d.  deutsch.  geol.  Gesellsch., 

vol.  XV,  pp.  127,  1-37. 

1864.  —       VESICULOSA,  8.  P.  Woodward.      Geol.  Mag.,  vol.  i,  p.  112,  pi.  v, 

fig.  6. 

1865.  —       VNCisEh-LA,  A.  Leymerie.     Bull.  Soc.  gcol.  de  France,  ser.  2, vol.  xxii, 

p.  367. 

1866.  —       (Gryph.*:a)    vesicularis,   K.   A.  Zittel.      Bivalv.    d.   Gosaugeb. 

(Denkschr.  Akad.  Wissensch.   Wien,   Math.-nat.   CI., 
vol.  XXV,  pt.  ii),  p.  123  [47],  pi.  xix,  fig.  6  (?  j>arf//»). 

1867.  —       VESICULARIS,  B.  Luiidgren.     Palaeont.  lakttag.  Filxekalk.  Liniluuan, 

p.  23. 
?    —  —  —  O.  Fraas.     Aus  dem  Orient,  i,  p.  88. 

?  1863.        —       HIPPOPODIUM,    E.    Eichimld.       Lethsea   Rossica,    vol.    ii,    p.    3f7, 

pi.  xix,  fig.  5. 

—  GRYPHJiiA  VESICULARIS,  Eichwcdd.     Ibid.,  p.  394. 


OSTREA.  3G:i 

1869.  OsTBEA  VESiciTLARis,  H.  Cuquaiid.     Mon.  Ostrea,  Terr.  Cn't.,  p.  35,  pi.  xiii, 

figs.  2—10. 

—  —         HIPPOPODIUM,  Coqiiand.    Ibid.,  p.  100,  pi.  xviii,  figs.  1,  4,  .^> ;  pi.  .\ix  ; 

pi.  XX,  tigs.  1 — 8. 

—  —       Lestjetjri,  Coquaud.     Ibid.,  p.  146,  j)!.  xli,  figs.  1—4. 

—  —        PROBOSCIDBA,   Coqwand.      IhU..   p.  72,  pi.  xv,  fig.  10  ;  pi.  xvi,  figs. 

1 — 12  ;  pi.  xviii,  figs.  1 — 5. 
_  _        vEsicuLARis,  E.  Favre.      Moll.  Foss.  de  Lemberg,  p.  160. 

—  —        HIPPOPODIUM,  Favre.     Ibid.,  p.  161. 

1870.  —  —  F.   Bonier.     Geol.  v.    Oberschles.,    p.  315,   pi.   xxxvii, 

fig.  7. 

—  —        VESICULARIS,   H.   Credner.     Zeitschr.  d.  deutscli.  geol.  Gesellsch., 

vol.  xxii,  p.  225. 
_  _  _  C.  Schliiter.     Neues  Jahrb.  fiir  Min.,  etc.,  p.  952. 

1871.  G-RYPHaiA  VESICULARIS,  F.  StoUczka.   Palseont.  Indica,  Cret.  Fauna  S.  India, 

vol.  iii,  p.  465,  pi.  xlii,  figs.  2 — 4;  pi. 
xliii,  fig.  1 ;  pi.  xlv,  figs.  7 — 12. 

1872.  Ostrea  hippopodium,  H.  B.   Geinitz.     Das   Elbtbalgeb.  in  Sauhsen  (Pal- 

fflontographiea,  vol.  xx,  pt.  1),  p.  177,  pl.xxxix, 
figs.  12—27 ;  pi.  xl,  figs.  1—3  ;  pt.  2,  pi.  viii, 
figs.  5—7. 

1873.  —        VESICULARIS,  /.  I.  LaJmsen.     Foss.  White  Chalk  of  Simbirsk  (Imp. 

Euss.  Miu.  Corps  Instit.),  pt.  2, 
p.  249. 

—  var.  JUDAicA,  L.   Lartet.      Auual.  Sci.  geol,  vol.  iii, 

p.  69,  pi.  xi,  figs.  8—10. 

187.5.        —  A.  J.  Jukes-Browne.     Quart.  Jouru.  Geol.  Soc,  vol. 

xxxi,  p.  295  (partim). 
?  1876.     Gryph.«:a  vesicularis  (?),   F.  B.  Meek.     Invert.  Cret.  and  Tert.  Foss.  U. 

Missouri,  p.  20,  pi.  xi,  fig.  2 ;  pi.  xvi,  fig.  8. 

Ostrea  hippopodium,   D.  Braiins.     Zeitschr.  f.  d.  ges.immt.  Naturwiss.,  ' 

vol.  xlvi,  p.  394. 

1877.        —  A.Frifsch.     Stud.  imGeb.  bijhmisch.  Kreideformat., 

ii,  Weisseuberg.  u.  Malnitz.  Sohicht., 
p.  140,  fig.  137. 
y   1878.        —        VESICULARIS,  0.  Fraas.     Aus  dem  Orient,  ii,  p.  86. 

—  J.  de  C.  Sowerbij,  in  F.  DLron.     Geol.  Sussex,  ed.  2, 

p.  386,  pi.  xxvii,  fig.  3, 
—        PvcNODONTA  VESICULARIS,  E.  BaijJe.      Explic.  Cai-te  geol.  France,  vol.  iv. 

Atlas,  pt.  1,  pi.  cxxxv,  figs.  1 — 7. 

—  proboscidea,  Bayle.     Ibid.,  pi.  cxxxvi,  figs.  1,  2. 

Ostrea  hippopodium,  C  Barrois.     Ann.  Soc.  gtol.  Nord,  vol.  v,  p.  407. 

—  G.  Behrens.     Zeitschr.    d.  deutsch.  geol.  Gesellscb., 

vol.  XXX,  p.  260. 
1881.     AvicuLA  filata,  R.  Etheridge,  in  Penning  and  Jukes-Browne.     Geol.  Cam- 
bridge, p.  144,  pi.  ii,  fig.  3. 
?  1882.     Ostrea  c/*.  HIPPOPODIUM,  If.  iriHf/m.J/Ze)-.     Jahrb.  d.  k.  preuss.  geol.  Landes- 

aiist.,  fiir  1881,  p.  29. 


564  CRETACEOUS   LAMELLIBRANCHIA. 

1882.     Gkyphjea  vesicitlaris,  H.  Schi-mh-r.     Zeitschr.  d.  deutsch.  geol.  Gesellscb., 

vol.  xxxiv,  p.  259. 

—  O.STREA  HiPPOPODiUM,  Schrikler.     Ibid.,  p.  269. 

1383.         —  __  yl.  Fritach.     Stud,  im  Geb.  buhmiscli.  Kreidefonnat., 

iii,  Isersehicht.,  p.  122,  fig.  98. 

1884.  Grtph.ba  vesicularis,  C.  A.  W/iitf.     4tli    Aun.  Eep.   TJ.  S.  Geol.  Survey, 

p.  303,  pi.  xlviii,  figs.  1 — 5. 

1885.  —  —  K.  P.  Whitfield.    Bracli.  aud Lamellibr.  Raritau Clays 

(Mon.  U.  S.  Geol.  Surv.,  vol.  ix),  p.  36,  pi.  iii, 
figs.  15,  16;  pi.  iv,  figs.  1 — 3;  pi.  v. 

1888.  —  —  G.  MiiUer.     Jalirb.  d.  k.  preuss.  geol.  Laudesanst., 

fur  1887,  p.  401. 

—  OsTREA  vesicularis,  A.   Peroii.      Hist.  Terr.    Craie  S.E.   Bassiu  Auglo- 

Parisien,  p.  179. 

1889.  —         (Geyphjea)  vesicularis,  0.  Griepenkerl.     Palseout.  Abliaudl.,  vol. 

iv,  p.  37. 
_  —         HIPPOPODIUM,    E.    Hohajpfel.       Die    Mollusk.    Aacheu    Kreide 

(  Palaeontographiea,  vol.  xxxv), 
p.  252,  pi.  xxix,  figs.  3 — 7. 

—  Gryph.*:a  vesicularis,  HoJzapfel     Ibid.,  p.  253,  pi.  xxix,  figs.  1,  2. 

1890.  —  —  M.  Blanckenliorn.     Beitr.  Geol.  Syrieus,  p.  75. 
1890-91.     OsTREA  HIPPOPODIUM,  A.  Peroii.      Bracliiopodes  etc.,  Terr.  Civt.  Hauts- 

Platoaux  de  la  Tuuisie,  p.  152. 
—  —      VESICULARIS,  Peroii.     Ibid.,  p.  175. 

?  1891.     Gryph.«a  VESICULARIS,  J.  Bolim.     Paleeoutograpliica,  vol.   xxxviii,   p.   91, 

pi.  iv,  fig.  3. 

—  OsTEEA  HIPPOPODIUM,  BoJim.     Ibid.,  p.  92,  pi.  iv,  fig.  12. 

1892.        —  E-  Stolley.     Mittheil.  a.  d.  Miii.  lustitut.  Univ.  Kiel, 

vol.  i,  p.  235. 

—  Gryph^ea  VESICULARIS,  Stollei/.     Ibid.,  p.  236. 

OsTREA  VESICULARIS,  F.   Vogel.     Verhaiidl.  nat.  Vercius  preuss.    KheiuL, 

vol.  xlix,  p.  51. 

1894.  —  —  A.  Hennig.     Geol.  Foreu.   i   Stockholm    Forliautll., 

vol.  xvi,  p.  513. 

—  —        HIPPOPODIUM,  Hennuj.     Ibid.,  p.  514. 

._  —        VESICULARIS,  J5.  imifZ^rcH.    MoWns^AMammiUatusodiMucronafa 

zouema,  p.  35. 

—  —        HIPPOPODIUM,  Liuulgren.     Ibid.,  p.  36. 

1895.  —        (Gryph.ea)  VESICULARIS,  F.  Vi>gel.     HoUiiudiseh.  Kreide,  p.  7. 

—  —        HIPPOPODIUM,  Vogel.     Ibid.,  p.  7. 

(Grypji^a)  HIPPOPODIUM,  E.  Tiessen.     Zeitsclir.  d.  <leutsfli.  geol. 

Gesellsch.,  vol.  xlvii,  p.  464. 

?    Geyph^a  VESICULARIS, /.  i'"".  T7/((<ertyecS.     Trans.  Roy.  Soc.  Canada,  ser.  2, 

vol.  i,  IX  120. 
1897.     OsTREA  HIPPOPODIUM,   A.  Heniiig.      llevis.  Lamellibr.  Nilssou's  "  Petrif. 

Suecana,"  p.  6.  pi.  i,  figs.  1—6,  8,  9. 

—       VESICULARIS,  Hell  nig.     Ibid.,  p.  18. 

HIPPOPODIUM,  R.  Leonard.     Palaeontographiea,  vol.  xliv,  p.  51. 


OSTREA.  365 

1897.  Grtph^ea  vesiculaeis,   F.  NotUny.     U.  Cret.  (Maestrichtian)  Mari  Hills 

(Palaeont.  ludica,  ser.  xvi,  vol.  i), 
p.  39,  pi.  X,  figs.  1,  2. 

—  OsTREA  VESicuLAEi.s,  A.  Rutot.    Bull.  Soc.  Beige  Gl'oI.  Pal.  et  Hyclrol.,  vol. 

X,  p.  26. 

—  —     HIPPOPODITJM,  Butot.     Ibid.,  p.  2t). 

1898.  —  —  G.  Mailer.     Molhiskoufauna  Uutersen.  v.  Eraun- 

scliweig  u.  Ilsede,  p.  14,  pi.  iii,  figs. 
10—15;   pi.  iv,  figs.  1,  2. 

1899.  . —  —  G.   de  Alessandri.       Paloeontogr.    Italica,   vol.   iv, 

p.  200. 

—  OsTREA  HIPPOPODIUM,  Alessaiidri.     Ibid.,  p.  199. 

1900.  OsTREA  (Gryph.ea)  VESiCTJLARis,  C.  jlfa7/er-£')//?(ai-.     Eclogae  Geol.  Helvet., 

vol.  vi,  p.  121. 

1901.  Gryph^a  vesicularis,  A.  Wollemann.     Jalirb.  d.  k.  preuss.  geol.  Landes- 

aust.,  vol.  xxi,  p.  14. 

1901.  Gryph^a  VESICULAEIS,  H.  ImJcrller.     Palasontograpliica,  vol.  xlviii,  p.  40, 

pi.  ii,  figs.  2 — 4  ;  pi.  iii,  figs.  7 — 9. 
1901-02.     OsTREA  (Ptcnodonta)  vesiculaeis,  p.  C/i'v/a^     Faim.  Cic't.  Portugal, 

vol.  i,  ser.  3,  p.  10:?, 
pi.  ii,  fig.  18. 

1902.  Gryph.ea  vesicularis,  A.  Wollemann.     Liiiieburg.  Kreide  (Abhandl.  d.  k. 

preuss.  geol.  Landesanst.,  n.f., 
37),  p.  52. 

—  Ostrea  hippopodidm,  /.  p.  /.  Eavn.     Mollusk.  i  Danmarks  Kridtafl.  I. 

Lamellil)r.,  p.  114. 

—  Gryph^a  vesicularis,  Bavn.     Ibid.,  p.  116. 

—  —  —  /.   Wanner.     Palseoutographica,   vol.    xxx   (2),    p. 

119,  pi.  xvii,  figs.  10—12. 

—  —  —  E.  Bacqnr.     Ibid.,  p.  188,  pi.  xxii,  figs.  1,  2. 

—  —  —  J.  A.  Taff.     Chalk  of  S.  W.  Arkansas  (22ud  Aiiu. 

Rep.  U.S.  Geol.  Surv.,  pt.  iii),  pis. 
1— Iii. 

1903.  Ostrea  vesicularis,  B.  Fortau.     Bull.  Inst.  Egyptieu,  scr.  4,  vol.  iv,  p.  308. 
?    —       Gryph^a    vesicularis,   /.   F.    Whiteaves.      Mesoz.    Foss.     (Geol.    Sin-v. 

Canada),  vol.  i,  p.  401. 

1904.  Pycnodonta  vesicularis,  H.  B<iin-!1U.     Mission  Scieut.  en  Perse  par  J.  de 

Morgan,  vol.  iii,  pt.  4,  Pak'ont., 
p.  278,  pi.  xxxvi,  fig.  23. 

1905.  GRYPH.a;A  vesicularis,  T.  Wecjner.     Zeitsihr.  d.  deutsch.  geol.  Gesellscli., 

vol.  Ivii,  p.  184. 

—  Ostrea  vesicularis,  A.  D.  Arkhangelsl-y.     Ann.  geol.  min.  Russie,  vol.  vii, 

pp.    190,    205,    pi.    iv,    figs. 
1,2. 

1906.  GRYPH.a:A   vesicularis,   E.  Biise.     Fauna   Senon.  Cardenas    (Bol.   Instit. 

geol.  Mexico,  No.  24),  p.  49,  pi.  iv, 
figs.  1 — 3  ;  pi.  vii,  fig.  2  ;  pi.  is,  fig.  4 ; 
pi.  xii,  tig.  6. 

48 


366  CRETACEOUS   LAMELLIBRAXCHIA. 

1906.  OsTBEA    (Gkyph^ea)    vesiculaeis,  M.   Bnule   and   A.   Thevenin.      Auual. 

PaleoDt.,  vol.  i,  p.  49  [7],  pi.  ii,  fig.  3. 
?    —       Gryphjsa  vesicularis,  /.  Pefhii.     PiilKontographica,  vol.  lii,  p.   188,  pi. 

xii,  figs.  2,  3. 

1907.  —        coNVEXA,  jS'.  Weller.     Cret.  Pal.  New  Jersey,  p.  451,  pi.  xlv. 

1910.  —        VESICULARIS,  F.  Freeh.     Neues  Jalirb.   fiir    Min.,  etc.,   i,  p.   (>, 

pi.  ii,  fig.  1 . 
?    — -        OsTREA  VESicuL.^Ris,  H.  Bfiiygeii.     Ibid.,  Bcil.-Baud  xxx,  p.  744. 

1911.  —        HippopoDiVM,  A.  FrifscJi.     Stud,  im  Geb.  bolimiscli.  Kreideformat., 

Korvcaner  Sehiclit.,  p.  48,  fig.  217. 
'r    —        Gryphea   vesicularis,   M.  E.    Tcuh'tsz.     Mitteil.  Jabrb.  uugarisch.  geol. 

Reichsanst.,  vol.  xix,  p.  110, 
pi.  iii,  fig.  3. 

—  Ostrea  hippopodium,    W.   lioyala.      Bull.  luternat.  Acad.  Sci.   Cracovie, 

p.  167. 

—  —  —  K.   Vogel  von  Falckenstein.     ZeitscLr.   d.  doutseb. 

geol.  Gesellsch.,  vol. 
Ixii,  p.  558. 

—  GrypHjEA  vesiculaeis,  v.  Falckenstein .     Ibid.,  j).  560. 

Non  1859.     Ostrea  vesiculaeis,  T.  Wiltshire.     Red  Chalk  of  Eugland  (Geol.  Assoc), 

p.  16,  pi.  ii,  fig.  5. 

Di'.'icriptii.Di. — The  left  valve,  when  attached  by  only  a  very  small  part  of  the 
vimljo,  has  a  grypheate  form,  being  nsnally  very  convex,  and  with  the  umbo 
prominent  and  incurved  ;  the  outline  of  the  valve  is  rounded,  but  the  posterior 
part  is  more  or  less  produced ;  the  postero-dorsal  part  is  often  convex  and  some- 
times distinctly  limited  from  the  remainder  of  the  valve ;  this  convex  part  when 
strongly  developed  may  be  produced  backwards  in  a  wing-like  form.  In  large 
specimens  of  the  grypheate  form  this  valve  becomes  very  thick. 

When  the  left  valve  is  attached  to  a  larger  .surface  of  more  or  less  rounded 
outline  it  is  still  grypheate  in  form,  but  with  the  umboual  region  truncated  owing 
to  the  attached  surface  being  flat  or  concave.  When  the  attached  surface  is  still 
larger,  relatively  to  the  entire  shell,  the  free  marginal  part  possesses  the  same 
character  as  the  corresponding  part  of  the  grypheate  form,  and  this  free  part 
grows  upwards  from  the  attached  surface.  When  nearly  all  the  valve  is  attached 
then  only  a  narrow  rim  grows  upwards  at  the  margin;  lastly,  in  some  cases  the 
entire  valve  is  attached  so  that  the  whole  of  it  is  flat  or  concave  ;  in  the  interior 
of  such  forms  a  few  distinct  concentric  ridges  are  often  found  at  intervals,  and 
from  the  outermost  of  these  the  marginal  part  of  the  valve  becomes  gradually 
thinner  and  usually  shows  a  porous  structure. 

^\'lien  the  left  valve  is  attached  to  a  cylindrical  or  other  elongate  object,  the 
form  of  the  shell  depends  on  the  direction  of  the  long  axis  of  the  attached  surface. 
If  the  axis  is  nearly  perpendicular  to  or  forms  a  considerable  angle  with  the  plane 


OSTREA. 


•667 


143 


■^^;-2Mi« 


\k^^ 


f' 


f 


'.r 


< 


FlQS.  143-153.— Osirea  vesicularis.  Lam.  HS-l-to.  Upper  Grc'ens;md  (zone  of  P.  asper),  Warminster. 
Museum  of  Practical  Geology,  Nos.  259-18,  25<).50.  US,  left  valve.  l-H,  right  valve.  145.  anterior 
view  of  144  showing  hoth  valves.  14(i.  Zone  of  ilicraster  coi-niif/iiiHioii,  'Witheringtou,  Dr. 
Blackmore's  Collection.  Interior  of  left  valve.  147.  Zone  of  Aciinocamax  quudratus.  East 
Hamham.  Same  Collection,  liight  valve.  The  left  valve  is  entirely  attached  to  the  convex 
surface  of  an  echinoid.  148,  14!).  Zone  of  ^^craster  cor-anfiuiniini,  Graveisend.  Hritish  Museum, 
No.  L.  20991.  Exterior  and  interior  of  a  left  valve.  l."jtAl53.  Zone  of  BeUmnilclla  murronata, 
Norwich.  150,  right  valve,  Britisli  Museum,  No.  L.  20616.  151,  Dorsal  view  of  l.JO  showing  both 
valves  ;  the  left  valve  entirely  attached  to  a  nearly  flat  surface.  152,  153.  Sedgwick  Museum. 
Left  and  right  valves.     146,  14",  natural  size.     Otlier  figures  x   J. 


:5(i8  CRETACEOUS    T.AMELEIBRANCHIA. 

(iF  the  valves  the  left  valve  becomes  convex;  if  the  axis  is  more  or  less  parallel  to 
the  ]ilaiie  of  the  valves  and  to  the  hinge-line  the  left  valve  is  less  convex;  and  if 
in  such  cases  the  attached  surface  is  mainly  in  front  of  the  umlx)  then  the  anterior 
part  of  the  shell  becomes  elongated,  whereas,  when  the  attached  surface  is  mainly 
posterior  to  the  umbo  the  posterior  part  of  the  shell  become  elongated  and  the 
shell  more  inequilateral ;  if  the  long  axis  of  the  attached  surface  extends  from  the 
umbo  in  a  postero-ventral  direction  the  shell  becomes  oljlique  and  very  inecjui- 
hiteral.  Occasionally  the  left  valve  shows  two  surfaces  of  attachment,  one  at  the 
uiul)o,  the  other  at  some  distance  from  it.  Since  the  direction  of  growth  depends 
mainly  on  the  position  of  the  attached  surface,  it  is  obvious  that  the  relative  length 
and  height  will  be  determined  in  the  same  way. 

The  surface  of  the  free  part  of  the  left  valve  is  smooth  except  for  growth- 
lines.  The  form  and  direction  of  the  umbo,  area  and  ligament-pit  depend  on  the 
mode  of  attachment.  The  ai-ea  is  either  nearly  parallel  to  the  attached  surface  or 
slopes  gently  from  the  hinge-line  to  the  umbo,  and  consequenth'  in  the  grypheate 
forms  it  eventually  l)ecomes  more  or  less  nearly  perpendicular  to  the  plane  of  the 
valves  of  the  adult  shell,  ])ut  in  completel}'  attached  forms  the  area  and  ligament- 
pit  remain  nearly  parallel  to  the  plane  of  the  valves  ;  between  these  two  extremes 
every  gradation  can  be  traced.  The  ligament-pit  and  the  nmbo  may  curve 
forwards  or  backwards,  or  be  perpendicular  to  the  hinge-line.  Small,  irregular, 
rouiideil  ridges  or  crenulations,  more  or  less  nearly  at  right  angles  to  the  margin 
of  tilt'  valve,  are  seen  on  the  inside  of  the  shell  on  each  side  of  the  area,  but  are 
most  developed  on  the  posterior  side.  The  adductor  impression  is  rounded  or 
slightly  oval. 

The  ri(j]tt  valve  in  the  grypheate  form  with  a  very  small  attached  surface  is 
almost  entirely  concave  or  sometimes  nearly  flat.  The  part  of  the  right  valve 
w  hieh  corresponds  to  the  attached  part  of  the  left  valve  is  more  or  less  convex, 
and  repioduces  the  detailed  markings  as  well  as  the  general  form  of  the  attached 
surface  ;  when  the  latter  is  flat  the  corresponding  part  of  the  right  valve  is  only 
slightly  convex,  and  its  convexity  increases  with  that  of  the  attached  surface.  As 
soon  as  the  left  valve  grows  free  from  the  attached  bodj^  the  corresponding  part  of 
the  right  valve  becomes  concave  and  grows  upwards  at  a  considerable  angle  with 
the  earlier  convex  part.  When  the  entire  left  valve  is  attached  the  whole  of  the 
i-ight  valve  is  slightly  convex  and  there  is  no  upward  growth  of  the  marginal  part. 
When  th(>  outer  layer  of  the  right  valve  is  well  pi'eserved  fine  thread-like  radial 
ribs  are  seen ;  they  are  widely  separated  and  cither  straight  or  slightly  irregular. 
The  inner  margin  near  the  area  has  small  ridges  like  those  of  the  left  valve. 

J//i/((7u'fe'.  —  The  study  of  a  large  series  of  specimens  shows  clearly  that  Osfnui 
hippopodlum,  Nilsson,  is  only  a  form  of  0.  vcniciil<iris  in  which  the  entire  or  almost 
the   entire   surface  of  the  left  valve  is   attached,  and  consecjuently  that  valve  is 


OSTREA. 


:](39 


Ficis.  lol-ltu  .—Os/rea  vesicularis, Lam.  Zone  of  Be!enini<e/(rt  nii(ci-oiia(a,  Norwich.  St-dgwick  Museum. 
Cauiliiidfje ;  except  15G,  157,  in  Dr.  Kowe's  collection.  1.54,  156,  159,  161,  lO:!,  Kit,  166,  left 
valves.  °  155,  right  valve  of  154.  157,  right  valve  of  1.56.  158,  interior  of  a  right  valve 
similar  to  157.  "  IW",  right  valve  of  15'J.  162,  right  valve  of  161.  165,  right  valve  of  164. 
167,  dorsal  view  of  166.     166  and  167,  natural  size.     Other  figures  x   J. 


370  CRETACEOUS   LAMELLIBRANCHIA. 

either  nearly  flat  (fig.  151)  or  grows  upward  near  the  margin  only  (fig.  l-i5), 
and  the  right  valve  is  either  slightly  convex  thi'oughout  (figs.  147,  150)  or  with 
a  narrow  marginal  part  growing  upwards  (fig.  155).  Although  this  type  differs 
greatly  in  appearance  from  the  grypheate  form  (fig.  182),  yet  every  stage  between 
the  two  extremes  can  be  seen  since  there  is  a  complete  gradation  from  forms  in 
which  the  entii'e  surface  is  attached  to  forms  in  which  only  a  ver^'  small  jmrt  of 
the  umbo  is  fixed.  But  whatever  the  form  of  the  shell  the  part,  if  any,  Avhich 
grows  free  shows  similar  characters.  This  view  of  the  relationship  of  (>.  hijijxi- 
/>ii(Iinni.  and  0.  rcsiciihrris  has  already  been  maintained  by  Peroii  (IS'.)O)  and  by 
Miiller  (18U8). 

In  the  Chalk  of  this  country  numerous  examples  of  the  left  valve  of  an  oyster 
attached  completely  to  flat  or  convex  objects  are  found  and  have  been  commonly 
referred  to  0.  Normaniana,  d'Orbigny^  (fig.  146).  The  right  valve  is  nearly  always 
missing.  The  marginal  part  of  the  left  valve  thins  away  rapidly  to  a  sharp  edge 
and  this  part  usually  shows  a  porous  structure,  whilst  on  the  inner  part  of  the 
valve  a  few  distinct  concentric  ridges  are  seen  ;  some  of  these  specimens  are  young 
individuals  and  many  are  probably  immature ;  the  concentric  ridges  probably 
indicate  the  beginning  of  an  upward  growth  of  the  margin  which  was  soon  dis- 
continued and  the  attached  growth  resumed.  Similar  concentric  ridges  are  present 
in  some  undoubted  examples  of  0.  ve.iicnlaris  (figs.  148,  149),  and  the  identity  of 
this  form  with  0.  venculavlti  is  proved  by  the  occasional  preservation  in  its  original 
position  of  the  right  valve  (Plate  LV,  fig.  4;  text-fig.  147)  showing  the  charac- 
teristic radial  ornamentation  of  0.  vesicularis.  A  left  valve  of  this  form  is  figured 
by  Geinitz"  as  0.  Inppoj^o'Uum. 

Avicula  filatn,  Etheridge,  from  the  Totternhoe  Stone  (zone  of  Holaster  snb- 
globosns)  of  Burwell,  is  founded  on  a  right  valve  of  a  small  specimen  of  0.  vesicx- 
laris,  and  shows  clearly  the  fine  radial  ribs.  It  agrees  with  small  specimens 
attached  throughout  or  with  only  the  margin  free,  found  in  the  Upper  and  Lower 
Chalk  as  well  as  in  the  Gault^  (Plate  LV,  figs.  4,  5,  7 ;  text-fig.  147). 

0.  clavata,  Nilsson,  is  a  form  in  which  the  posterior  part  is  more  produced  than 
usual  owing  to  the  position  of  the  attached  surface. 

The  liippopodinm  form  of  0.  vesicularia  found  in  the  Cenomanian  Avas  named 
0.  Leftncnr'i  by  d'Orbigny  on  account  of  its  lower  horizon.  But  Hennig,  who  has 
studied  a  series  of  Cenomanian  specimens,  sees  no  reason  for  separating  it  from 
the  Senonian   examples,  and  Miiller  (1898)  likewise  includes  it  in  0.  ro^icuhtrh. 

•  '  Pal.  Frau9.  Terr.  Cn't.,'  vol.  iii  (1847),  p.  746,  pi.  cccclxxxviii,  figs.  I— 3. 

-  •  Palseoutogriqiliica,'  vol.  xx,  pt.  2,  pi.  viii,  fig.  6. 

^  Anomia  mihrailiata,  Eeuss,  is  probably  a  small  fxam^jle  of  0.  rcslnilarif  similar  to  Avicula 
Jilala  of  Etheridge.  Eeuss,  'Die  Versteiu.  der  biihm.  Kreideformat.,'  pt.  2  (1846),  p.  45,  jjI.  x.\xi, 
fig.  19. 


OSTREA. 


371 


180 


Figs.  KiS-lSl. —Osfroa  vesicnlaris,  Lam.  Zone  of  lichnmitella  mi(rcoiia/rt,  Noi'wicli.  10S>,  Iti'.l,  left  ami 
riflht  valve.s.  Norwich  Museum,  No.  2133.  170,  171,  left  and  light  valves.  Dr.  Kowe's  Collection. 
172,  173,  left  and  right  valves.  Sedgwick  Museum.  171-,  17.5,  left  and  right  valves.  Norwich 
Museum.  17G-179,  left  valves.  Sedgwick  Museum.  178,  posterior  view  of  177.  ISO,  181,  left 
valve.     Dr.  Kowe's  Collection.     181,  anterior  view  of  180.     All  x   J. 


372  CRETACEOUS   LMIELLIBRAXCHIA. 

0.  prohosddra,  d'Arcliiac,  is  included  b}'  Zittel  and  by  G.  Midler  in  0.  vesiadaris, 
and  the  latter  points  out  its  probable  close  connection  with  0.  biatn-ictilata, 
Lamarck.  The  type  of  0.  prohosciilea  from  the  Santonian  of  Saintes,  Dordogne,  is 
not  quite  satisfactory,  but  most  of  the  specimens  figured  by  Coquand  seem  to  be 
inseparable  from  0.  vesiciilnris. 

The  grypheate  forms  of  0.  vpakiilariA  have  been  usually  placed  in  the  "  genus  " 
Clri/ph.va,  and  the  hippopodutm  forms  in  Odrea;  in  the  case  of  this  species,  at  any 
rate,  "  Gri/phssa  "  canrwat  be  accepted  as  a  genus. ^ 

In  the  Lower  Chalk  (Plate  LV,  figs.  8,  9)  a  small  grypheate  form"  varying 
only  to  a  small  extent  in  dimensions  is  common  and  is  not  usually  associated  with 
larger  forms ;  the  uniformity  in  size  and  character  of  this  form  at  first  give  the 
impression  that  it  may  be  a  distinct  variety,  but  comparison  with  the  small  forms 
of  0.  vesicularis  from  the  Upper  Chalk  (figs.  166,  1G7)  shows  that  they  cannot  be 
separated ;  their  small  size  was  probably  due  to  local  conditions.  Further,  it  may 
be  noted  that  in  earlier  beds  (the  Upper  Greensand)  large  forms  of  butli  the 
grypheate  and  hippopocUum  types  occur  (figs.  143 — 145),  and  are  indistinguishable 
from  those  found  in  the  Upper  Chalk.  Some  rather  small  grj'pheate  forms  are  also 
found  in  the  Gault  and  Cambridge  Greensand,  and  also  forms  with  all  or  the  larger 
part  of  the  left  valve  attached,  but  they  are  not  common  in  the  Gault. 

A  few  specimens  of  a  small  oyster  have  been  found  in  the  Lower  Greensand  of 
Atherfield  and  Shanklin,  and  show  the  fine  radial  ribs  on  the  right  valve^ ;  some 
of  these,  and  probably  all,  are  examples  of  0.  rcsinthtri^:,  but  the  left  valves  are 
not,  in  all  cases,  well  preserved.* 

Remarks. — 0.  veundaris  attains  its  greatest  development  in  the  zones  of 
BeJemnitdla  vmcronala  and  Ostrea  lunata  in  this  country,  Avhere  the  grjqjheate 
forms  are  abundant  and  reach  a  large  size.  The  form  with  the  posterior  wing- 
like projection  (figs.  174-179)  occurs  mainly  in  the  zone  of  7)'.  mncronatn.  0.  /•",>■/- 
cularis  has  been  observed  attached  to  sponges,  corals,  echinoids,  oysters,  Iiioceramus, 
Spondi/lus,  gasteropods.  Ammonites,  and  Belemnitella.  The  long  range  in  time 
and  the  wide  geographical  distribution  of  this  species  have  already  been  noted  by 
Hennig  and  other  authors. 

Tiipps. — 0.  vesmdari.i,  Lamarck,  and  0.  ddtoide.a,  Lamarck,  from  the  Upper 
Chalk  of    Men  don.      Gri/phsea   globo.m,   Sowerby,  from  the  zone  of  Belemnitella 

'  Tliis  conclusion  is  in  agreement  with  Peron's  views  on  the  "  genera  "  of  the  Ostreidfe ;  see 
'  Descript.  Bracli.,  etc.,  Terr.  Cret.  Tunisie'  (1890—111),  pp.  107—109. 

2  A  similar  but  rather  larger  form  occurs  in  the  Melbourn  Eock  and  [Aen  Ms-niarls. 

'  Examples  of  this  are  figm-ed  in  vol.  i,  pi.  v,  figs.  4,  6 

■*  Ostrea  vinjafa,  Sowerby,  possesses  numerous  fine  radial  ribs.  The  type  is  the  only  specimen 
known  ;  it  was  found  in  the  Lower  Chalk  (probably  zone  of  Holaster  gubglohosus)  of  Sussex.  The 
aflSnities  of  this  form  cannot  be  determined.     Dixon,  '  Geol.  Sussex '  (1850),  p.  357,  pi.  xxvii,  fig.  1. 


OSTRBA. 


0{- 


umcronata  of  Norwich,  is  in  the  British  Museum.  0.  hippopodlnm,  Nilsson,  from 
the  Upper  Chalk  of  Kopingc,  is  in  the  Lund  ]\Iuscuin.  The  specimens  of  0.  hippo- 
jjudiuiu  figured  by  Goldfuss  from  the  Cenomanian  of  Ussen,  are  in  the  Munich 
Museum.  The  examples  of  0.  vesicular i.i  figured  by  William  Smith  came  from 
Norwich  and  are  in  the  British  Museum.  Tlie  original  of  (hijplixa  (jlohosa  var. 
depressa,  Sowerby  (in  Dixon),  cannot  be  found  ;  the  specimens  of  O.S'frea  figured  by 
the  same  author  (Dixon,  pi.  xxviii,  figs.  22,  23),  from  the  zone  of  Holastersuhgloho.^iis 
near  Warminster,  are  in  the  British  ]\luseum.  The  specimen  figured  by  S.  P. 
Woodward  as  0.  vesiculosa  from  the  Upper  Chalk  of  Sussex,  is  also  in  that  Museum. 
Acicula  filata,  Etheridge,  from  the  Totternhoe  Stone  of  Burwell,  is  in  the  Sedgwick 
Museum. 


Fio.  182. — Osd-ea  fc»'icK?aris,  Lam.     Zone  of  Osfrea  ZunaJa,  Triminghani.     Dr.  Rowe's  Collection.     Left 

valve.      X  J. 


Distiihntion. — Lower  Greensand  (Ferruginous  Sands)  of  Shanklin.  Gault  of 
Folkestone.  Cambridge  Greensand.  Upper  Greensand  (zone  of  Schlmnbachia 
rostrata)  of  the  Isle  of  Wight.  Upper  Greensand  (zone  of  Pecten  aspcr)  of  War- 
min.ster. 

Chalk  Marl  (zone  of  SrhhenJiarida  rarians)  of  Folkestone,  Offham,  and  Burwell. 
Cenomanian  (Meyer's  bed  11)  of  Beer  Head.  Cenomanian  Sandstone  of 
Wilmington. 

Zone  of  Holaster  suhijlohosus  of  Chilcomb  (IIant.s),  Glynde  (Lewes),  Burham, 
Arlesey,  Ickleford  (near  Hitchin),  Cheri-y  Hinton,  Burwell,  and  Isleham. 

Zone  of  Rhi/iichonelli  Gavieri  of  the  South  Devon  coast  and  Dover.  Melbourn 
Rock,  ^lelbourn. 

49 


374  CRETACEOUS   LA:\1ELLIBRAXCTII.\. 

Zone  of  'I'cn'bratiiliiKi  laid  of  the  South  Devon  coast,  Dover,  Cnxtoii,  Charing, 
and  Beachy  Head. 

Zone  of  Hola.tter  flniinH  of  Mujae  Baj',  Borstal,  "West  Wratting,  Cheveley,  and 
Swaffham  (Norfolk). 

Zone  of  MirrdKfrr  cor-tedndmarinmoi  Borstal  Manor,  Chatham,  and  Stevenage. 

Zone  of  Micrnster  cnr-augulmtin  of  Witherington,  Qnidliiiinpton,  Cnni])  Hill 
(near  Salisbury),  Northfleet,  Gravesend,  and  the  Thanet  coast. 

Zone  of  Marsvjntos  fcfitudinarmH  of  the  Thanet  coast.  TJiiiiiirriinis  l)an(l  of 
Devizes  Road  (Salisbuiy). 

Zone  of  AcH'iKinima.v.  i[i(ailrntiii<  of  "Whaddon,  East  and  West  Haruhani,  Fareham, 
Shawford,  and  Bishops  Waltham. 

Zone  of  Belemnitclln  mucrondta  of  the  Dorset  coast  and  Norwich. 

Zone  of  Ostrea  Innnta  of  Trimingham. 


OsTKKA  VESiciu.osA  {Suicerhi/),  1822.     Plate  LV,  figs.  lU— 11;  Plate  LVI,  fig.  1. 

1822.     Gryph^a  vesiculosa,  J.  Soirei-bi/.     Min.  C'oiu-li.,  vol.  iv,  p.  9-],  [.I.  ccc-l.\ix. 
?   1847.     OsTREA  VASCULUM,  A.  (VArcliiac.     Mrm.  Soc.  f;i'ol.  de  France,  ser.  2,  vol.  ii, 

1>.  312,  pi.  xvi,  figs.  5,  6. 
184:fl.     Grypha:a   vesiculosa,    T.  Brown.      Illustr.    Foss.    Couch.   Gt.   Brit,   ami 

Ireland,  p.  149,  pi.  Ixi,  figs.  8,  9. 
18.50.     OsTREA   VESICULOSA,    E.    Gurvanger.      Bull.  Soc.  ffcol.  de  Frauce,  ser.   2, 

vol.  vii,  p.  802. 
1854.     Gryph.s:a  vesiculosa,/.  Morris.     Cat.  Brit.  Foss.,  ed.  2,  p.  168. 
?  1868.     Ostrea   columba,  A.  Briart  and  F.  L.   Corvef.     Meule  de  Bracqiiegnies 

(Mem.  cour.  et  Mem.  des  Sav.  etrangcrs,  vol.  xxxiv), 
p.  46.  pi.  iv,  figs.  1.3—15. 
1869.  —       vesiculosa,  H.  Coqnnnd.     Hon.  Ostrea,  Terr.  Cn't.,  p.  152,  pi.  lix, 

figs.  4—7. 
1871.  —  —  F.  J.  Pictef  and  G.  Camjnchc.     Foss.  Terr.  Cn't.  Ste. 

Croix  (Maier.  Fal.  Suisse,  ser.  5),  p.  311,  pi.  exciv, 
figs.  1 — 6. 
—        Gryph^.a  vesiculosa,  i^.  S/o/ffz/i-ff.    Palffiont.  Indica,  Cret.  Fauna  S.  India, 

vdl.  iii,  p.  466,  pi.  xxxix,  figs.  1,  2. 
1882.  —  —  G.  Segnenxn.     Atti  R.  Accad.  Lincei,  ser.  3,  CI.  Sci. 

Fis.  Math.,  vol.  xii,  p.  182,  i)l.  xix,  fig.  2. 
1890-91.     OsTRKA  vesiculosa,  a.  Peron.     Descript.  Braeh.,  etc  ,  Terr.  Cn't. 'J'uuisie, 

p.  126. 
1903,  —  —  Ii.  Fortau.     Bull.  Inst.  f;g_vptieu,  ser.  4,  vol.  iv,  p.  290. 

?  1908.     GryphjEA  ff/?'.  VESICULOSA,  f.  Fai-re.     Neues  Jahrb.  fiir  Min.,  etc.,  Beil.-Bd. 

x.vv,  p.  609. 

Non  1864.     Ostrea  vesiculosa,  S.  P.  Woodward.     Geol.  Mag.,  vol.  i.  p.  112.  i>l.  v,  fig.  6. 


OSTREA.  375 

DescripfioiL—Lah  valve  usually  tliick,  very  convex,  grypheate,  more  or  less 
oval,  height  usually  considerably  greater  than  the  length ;  slightly  or  moderately 
ine(|uilateral,  sometimes  with  a  rounded  ridge  extending  from  the  umbo  to  the 
postero-ventral  extremity.  Posterior  part  often  convex  and  separated  from  the 
reiuainder  of  the  valve  l)y  a  furrow.  Umbo  sharp,  prominent,  more  or  le.ss 
incurved,  and  usually  witli  a  small  posterior  curvature;  surface  of  attachment 
generally  small.  Area  and  ligament-pit  high,  straight  or  with  a  small  backward 
curvatui-e.  Adductor  impression  oval  or  rounded.  Right  valve  thin,  concave. 
Surface  of  both  valves  smooth,  except  for  growth-lines. 

Abilities. — This  species  is  closely  allied  to  0.  vesicularix,  but  the  umbo  is  more 
pointed,  usually  less  incurved  and  with  a  smaller  attached  surface;  the  area  is 
higher,  and  usually  the  height  of  the  shell  is  relatively  greater  in  proportion  to  its 
length.  Most  of  these  differences  are  probably  to  be  accounted  for  by  the  small 
size  of  the  attached  surface. 

Tiipe. — From  the  Upper  Greensand  of  AVarininster,  in  the  British  Museum. 

DUtvibntiiin. — Upper  Greensand  :  common  in  the  zone  of  Scldoenhachia  rostrata 
of  Ventnor,  Warminster,  Dinton  and  Potterne;  rare  in  the  zone  of  Fcxti'ii  nxpar 
of  Ventnor,  Warminster,  and  Ballard  Down  (Swanage).  Chloritic  Marl  of 
Coinptou  Bay,  Isle  of  Wight. 


OsTKKA  CAXALKULATA  {Soivcrbi/),  181:5.     Plate  LVI,  figs.  2-10. 

1813.     Chama  canaliculata,  /.  Soiiyrhi/.      Miu.  Conch.,  vol.  i,  p.  68,  \>\.  xxvi,  tig.  1 

(uou  Oslrea  canaliculata,  Sowerb}'.) 
1821.  OsTREA  CANALICULATA,  M.  J.  L.  Defiance.  Diet.  Sci.  luit.,  vol.  xxii,  ]>.  26. 
18-27.     OsTBEA  LATERALIS,  5".  Nilssoti.     Petrific.  Suecaua,  p.  29,  pi.  vii,  tigs.  7 — 10. 

—  Chama  conica,  Nilsson.     Ibid.,  p.  28,  pi.  viii,  tig.  4. 

1829.     Gryph.«a  canaliculata,  J.  de  C.  Sowerhij.     Miu.  Couch.,  vol.  vi,  p.  218. 

—  Exogyra  undata,  Sowerhy.     Ibid.,  vol.  vi,  p.  220,  pi.  dcv,  figs.  5 — 7. 
1833.     OsTREA  lateralis,  a.    GohlJ'uxx.      Petref.  Genu.,  vol.  ii,  p.  24,  \A.  Ixxxii, 

%.  1. 
y  1834.     GRVPH.tiA  VOMER,  S .  G .  Mortoii.     Synopsis  Organic  Remains  Cret.  U.  States, 

p.  54,  j>l.  ix,  fig.  5. 
1837.     OsTREA  LATERALIS,  \V.  HIkI ii(jei\     Letliaea  Sueeica,  p.  4ti,  pi.  xiii,  fig.  1. 

—  Ami'uiuonte  undata,  G.  G.  Punch.     Polens  Pahiout.,  ]>.  39. 

1842.     Exogyra  parvula,  A.  Leijmerie.     Ml'iu.  Soc.  gc'ol.  de  France,  ser.  2,  vol.  v, 

p.  17,  pi.  xii,  figs.  8,  9. 
1845-6.     OsTREA  lateralis.  If.  B.  Geinitz.     Grundriss  d.  Versteiu.,  p.  480,  pi.  xx, 

fig.  22. 

1846.  Exogyra  laterali.s,  A.  E.  Rcukk.     Die  Versteiu.  der  biihui.  Kreideforuiat., 

pt.  2,  p.  42,  pi.  xxvii,  figs.  38 — 47. 

1847.  Ostrea   canaliculata,    .1.    il'Orhiijuij.      I'al.  Franc.  Terr.   Crct.,  vol.  iii, 

]<.  709,  pi.  cccclxxi,  figs.  4—8. 


:!?(;  CRETACEOUS    LAMEF.LIHHANCHIA. 

1847.     ExoGYRA  LATEitALrs,  J.  Muller.     Petref.  der  Aacbeu.  Kreidof.,  j)t.  1,  p.  40. 

1849.  Gryph«a    undata,    T.     Brovn.        Illu.str.     Foss.    Conch.,     6t      Britain 

and  Ireland,  p.  149,  pi  Ix,  fis^s.  14.  1.5. 

—  —  canaliculata,  Brown.     Ibid  ,  p.  149,  pl.  Ixi,  lig.  18. 

1850.  OsTEEA  canaliculata,  a.  <VOrhi(jny.     Prodr.  de  Pal.,  vol.  ii,  pp.  139,  170, 

2.55. 
?   1852.         —        CTRToMA,  E.   Kiier.      Deukschr.  Akad.  Wissenseh.  Wieu  ,  Matli.- 

iiat.  CI.,  vol.  iii,  p.  820,  p!.  xvii,  fig.  11. 

1853.  —        CANALICULATA,  F.  J.  Flcli't  1111(1  W.  Rovx.     MoU.  Foss.  Gres  verts 

de   Geneve,   p.  522, 
pl.  1,  fig.  2. 

1854.  —  —  J.  M<.r)ii<.     Cat.  Brit.  Foss.,  ed.  2,  p.  173. 

EXOGYEA  LATERALIS,  jJ/orriV.      Ibid.,  p.  I(i7. 

1863.     OsTREA  LATERALIS,  A.  V.  Stromheclc.     Zcitschr.  d.  deutsch.  gcol.  Gt'sellscli., 

vol.  XV,  p.  110. 

—  ExoGTRA  LATERALIS,  H.  Breschef.     Ibid.,  vol.  xv,  p.  357. 

1867.  OsTREA  L.VTERALis,  B.  LmHhjreu.     Palteont.  lakttag.   Fiixekalk.  Liniliamn. 

p.  23. 

1868.  ExoGYRA  LATERALIS,  E.  Eicliwahl.     Letlisea  Rossica,  vol.  ii,  p.  398. 

1869.  OsTREA   CANALICULATA,  //.    Ciiquciiid.      Mou.  Ostiea,  Terr.  Crt't.,  p.   128, 

pl.    xlv,  figs.    13,   14;    pl.    xlvii, 
figs.  7—10;  il,  Iii.  fig.  l-i;  pl.  Ix. 
figs.  13—15. 
— •  —  LATERALIS,     Coqiiaiid.       Ibid.,  p.   96,    pl.    xviii,   tig.    12  ;    1>1.    xxx. 

figs.  10-14. 

1870.  ExoGYRA   LATERALIS,  F.    Bi'mcr.     Geol.  V.   Oberschles.,  p.  341,   jil.   xxix. 

figs,  4,  5. 
?     —       OsTREA    LATERALIS,    H.    Crechier.      Zeitsflir.  d.  deutsch.  geol.   Gesellsch., 

vol.  xxii,  p.  228. 
1S71.         —         cxyxhicvLkTA,  F.J.  Picf  el  atid  G.  Cirm2>lc/ie.    Foss.  Terr.  Cn't.  Ste. 

Croix  (Alater.  Pal. 
Suisse,  ser.  5), 
p.  305,  pl.  exeiii. 
figs.  4 — 14. 

—  ExoGYRA  CANALICULATA,  F.   Sloliczla.     raltcont.  ludica,   Cret.   Fauna  S. 

India,  vol.  iii,  p.  463,   pl,  xlviii. 
figs.  6—8. 
1872.     OsTREA  (Kxooyra)  LATERALIS,  H.  B.  Geitiitz.     Das  Elbthalgeb.  in  Sachsen 

(Palseontograpliica,    vol. 
XX,  pt.  i),  p.  179,  i>l.  xli. 
figs.   28—35  ;  pt.  ii,    pl. 
viii,  figs.  15 — 17. 
1877.     ExoGYRA  L.VTERALis,  A.  FfihcJi.     Stud.  iiu  Geb.  biJhmisch.  Kreideforniat.. 

ii,  Weissenberg.  u.  Malnitz.  Schiclit., 
p.  140,  fig.  136. 

1881.  OsTREA    LATERALIS,  J.  Gosselet.      Esquisse  geol.  du  Nord,  pl.  xvii,  fig.  14. 

1882,  ExoGYRA  LATERALIS,  H.  Scliroder.     Zoitsclir.  d.  deutsch.  geol.  Gesellsch.. 

vol.  xxxiv,  p.  261. 


OSTEEA.  37  r 

1882.  ExooYKA  cANALicuLATA,  G.  Setjiieiizd.      Atti  E.  Accad.  Lincei,  ser.  3,  CI. 

Sci.  Fis.  Math.,  vol.  xii,  p.  17G. 

1883.  —         LATERALIS,     FrilKch.     Op.  cit.,  iii,  Isersehicht.,  p.  118. 

?  1887.  —         rf.  LATERALIS,  F.  Frcch.     Zeitschr.  d.  deutsch.  geol.  Gesellsch., 

vol.  xx.xix,  p.  153. 

1888.  OsTREA    CANALicuLATA,    A.    Peroii.      Hist.    Terr,    de   C'l-aie    S.E.    Ba.s.sin 

Anglo-Parisien,  p.  175. 

—  ExoGTRA  CANALICULATA,  G.  MUllcf.     Jalirl).  d.  U.  pivuss.  geol.  Landesanst. 

fill-  1887,  p.  401. 

1889.  ExoGVEA  LATERALIS,  FrlffcJi.     Op.  cit.,  iv,  Teplitz.  Sehifht.,  p.  86. 

—  OsTREA   (Exogyka)    LATERALIS,   O.    Grirjffnkerl .      Seuou  v.    Kouigslutter 

(Palaeout.    Abbaudl.. 
vol.  iv),  p.  36. 

—  ExoGYEA  LATERALIS,  E.  Holzapfel.     Die  Mollu!,];.  Aaclieu.  Kveide  (Pala;on- 

tographica,  vol.  xxxv),  p  256. 
1890—91.     OsTREA  CANALICULATA,  A.  Pewii.     Desciipt.  Braehiop.,  etc.,  Terr.  Cn't. 

Tunisie,  p.  163. 

1893.  ExoGTRA  LATERALIS,  Fritscli.     Op.  fit.,  PHeseii.  Sfliicht.,  p.  102. 

1894.  OsTREA    LATERALIS,   A.    Hemiiy.     Geol.    Fiiren.    i    Stockliolm,    ForbaiulL, 

vol.  xvi,  p.  513. 

1895.  —         (Exogyea)  LATERALIS,  F.  To(jel .     Hollandisch.  Kreide,  p.  13. 

'■     —  ExoGYRA   (■/".    CANALICULATA,    E.    Tiegseit.     Zsitsclir.    d     deutsfh.    geul. 

Gesellsch.,      vol.       xlvii, 
p.    465. 

1896.  OsTEEA  CANALICULATA,   A.  J.  J tikt's-Brovne  and  W.  Hill.      Quart.  Jourii. 

Geol.    Soc,    vol. 
Iii,  p.  149. 

1897.  —       LATERALIS,   A.   Helm!,/.     Eevision    Lamellibr.   i  Nilssous  'Petrif. 

Sueeaua,'  p.  23. 

—  ExoGYRA  LATERALIS,  Fritscli.     Op.  cit.,  vi,  Chlomek.  Schicht.,  p.  68. 

—  —  —  R-  LeonhanJ.     Palseonlographica,  vol.  xliv,  p.  .".0. 

—  —  —A.  Rutot.     Bull.  Soc.  Beige  Geol.  Pal.  et  Hvdml..  vol.  x, 

p.  27. 

—  —        cAHAmcvLATA,  B.  B.  Newton.     Proe.  Dorset  Nat.  Hist,  and  Antiq. 

Field  Club,  vol.  xviii.  p.  91,  pi. 
iii,  figs.  7,  8. 

1898.  OsTEEA  CANALICULATA,  B .  Foiidii.     Bull.  Inst.  Egyptien,  ser.  4,  vol    iv, 

p.  292. 

—  Exogyea  LATERALIS,  G.  Midler.      Mollusk.  Uuterseu.  v.  Brauusehweig    u. 

Ilsede  (Abhandl.  d.  k.  preuss.  geol. 
Landesanst.,  n.f.,  25),  p.  15,  pi.  iii. 
fig.  2. 

—  —  —  0.  M.  Eels.     Geognost